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20807620 = 2251040381
BaseRepresentation
bin100111101011…
…1111111000100
31110011010200121
41033113333010
520311320440
62021551324
7341601421
oct117277704
943133617
1020807620
1110822089
126b75544
134406c02
142a98d48
151c6034a
hex13d7fc4

20807620 has 12 divisors (see below), whose sum is σ = 43696044. Its totient is φ = 8323040.

The previous prime is 20807597. The next prime is 20807621. The reversal of 20807620 is 2670802.

It can be written as a sum of positive squares in 2 ways, for example, as 5456896 + 15350724 = 2336^2 + 3918^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20807621) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 520171 + ... + 520210.

It is an arithmetic number, because the mean of its divisors is an integer number (3641337).

Almost surely, 220807620 is an apocalyptic number.

20807620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20807620 is an abundant number, since it is smaller than the sum of its proper divisors (22888424).

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

20807620 is a wasteful number, since it uses less digits than its factorization.

20807620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1040390 (or 1040388 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 20807620 is about 4561.5370216628. The cubic root of 20807620 is about 275.0473527273.

The spelling of 20807620 in words is "twenty million, eight hundred seven thousand, six hundred twenty".

Divisors: 1 2 4 5 10 20 1040381 2080762 4161524 5201905 10403810 20807620