20056640 has 56 divisors (see below), whose sum is σ = 48143160. Its totient is φ = 7958528.

The previous prime is 20056607. The next prime is 20056669. The reversal of 20056640 is 4665002.

It can be written as a sum of positive squares in 4 ways, for example, as 200704 + 19855936 = 448^2 + 4456^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74426 + ... + 74694.

Almost surely, 2^20056640 is an apocalyptic number.

20056640 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 20056640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24071580).

20056640 is an abundant number, since it is smaller than the sum of its proper divisors (28086520).

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

20056640 is a wasteful number, since it uses less digits than its factorization.

20056640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 519 (or 509 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 20056640 is about 4478.4640224077. The cubic root of 20056640 is about 271.6977611708.

The spelling of 20056640 in words is "twenty million, fifty-six thousand, six hundred forty".