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20388808 = 2311415651
BaseRepresentation
bin100110111000…
…1101111001000
31102100212012001
41031301233020
520204420213
62005000344
7335205406
oct115615710
942325161
1020388808
1110566460
1269b30b4
1342bb3ab
1429ca476
151bcb1dd
hex1371bc8

20388808 has 32 divisors (see below), whose sum is σ = 42729120. Its totient is φ = 9040000.

The previous prime is 20388803. The next prime is 20388811. The reversal of 20388808 is 80888302.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20388803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 783 + ... + 6433.

It is an arithmetic number, because the mean of its divisors is an integer number (1335285).

Almost surely, 220388808 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20388808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21364560).

20388808 is an abundant number, since it is smaller than the sum of its proper divisors (22340312).

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

20388808 is a wasteful number, since it uses less digits than its factorization.

20388808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5709 (or 5705 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 37.

The square root of 20388808 is about 4515.3967710490. The cubic root of 20388808 is about 273.1894635824.

The spelling of 20388808 in words is "twenty million, three hundred eighty-eight thousand, eight hundred eight".

Divisors: 1 2 4 8 11 22 41 44 82 88 164 328 451 902 1804 3608 5651 11302 22604 45208 62161 124322 231691 248644 463382 497288 926764 1853528 2548601 5097202 10194404 20388808