20557256436 has 48 divisors (see below), whose sum is σ = 53654328000. Its totient is φ = 6806424096.

The previous prime is 20557256431. The next prime is 20557256437. The reversal of 20557256436 is 63465275502.

20557256436 is a `hidden beast` number, since 2 + 0 + 5 + 57 + 2 + 564 + 36 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 20557256391 and 20557256400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20557256431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 622650 + ... + 654833.

It is an arithmetic number, because the mean of its divisors is an integer number (1117798500).

Almost surely, 2^20557256436 is an apocalyptic number.

It is an amenable number.

20557256436 is an abundant number, since it is smaller than the sum of its proper divisors (33097071564).

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

20557256436 is a wasteful number, since it uses less digits than its factorization.

20557256436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1277645 (or 1277637 counting only the distinct ones).

The product of its (nonzero) digits is 1512000, while the sum is 45.

The spelling of 20557256436 in words is "twenty billion, five hundred fifty-seven million, two hundred fifty-six thousand, four hundred thirty-six".