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20000000 = 2857
BaseRepresentation
bin100110001001…
…0110100000000
31101122002211202
41030102310000
520110000000
61552400332
7331666016
oct114226400
941562752
1020000000
1110320329
1268460a8
1341b3427
1429288b6
151b50dd5
hex1312d00

20000000 has 72 divisors (see below), whose sum is σ = 49902216. Its totient is φ = 8000000.

The previous prime is 19999999. The next prime is 20000003. The reversal of 20000000 is 2.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 4 ways, for example, as 19784704 + 215296 = 4448^2 + 464^2 .

It is a sliding number, since 20000000 = 10000000 + 10000000 and 1/10000000 + 1/10000000 = 0.00000020000000.

It is a Harshad number since it is a multiple of its sum of digits (2).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20000003) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3999998 + ... + 4000002.

Almost surely, 220000000 is an apocalyptic number.

20000000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24951108).

20000000 is an abundant number, since it is smaller than the sum of its proper divisors (29902216).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20000000 is an frugal number, since it uses more digits than its factorization.

20000000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51 (or 7 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 2.

The square root of 20000000 is about 4472.1359549996. The cubic root of 20000000 is about 271.4417616595.

The spelling of 20000000 in words is "twenty million", and is thus an aban number and an uban number.

Divisors: 1 2 4 5 8 10 16 20 25 32 40 50 64 80 100 125 128 160 200 250 256 320 400 500 625 640 800 1000 1250 1280 1600 2000 2500 3125 3200 4000 5000 6250 6400 8000 10000 12500 15625 16000 20000 25000 31250 32000 40000 50000 62500 78125 80000 100000 125000 156250 160000 200000 250000 312500 400000 500000 625000 800000 1000000 1250000 2000000 2500000 4000000 5000000 10000000 20000000