20657312456 has 16 divisors (see below), whose sum is σ = 42253593840. Its totient is φ = 9389687440.

The previous prime is 20657312453. The next prime is 20657312503. The reversal of 20657312456 is 65421375602.

It is not an unprimeable number, because it can be changed into a prime (20657312453) 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, 117371006 + ... + 117371181.

It is an arithmetic number, because the mean of its divisors is an integer number (2640849615).

Almost surely, 2^20657312456 is an apocalyptic number.

It is an amenable number.

20657312456 is an abundant number, since it is smaller than the sum of its proper divisors (21596281384).

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

20657312456 is a wasteful number, since it uses less digits than its factorization.

20657312456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234742204 (or 234742200 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 41.

The spelling of 20657312456 in words is "twenty billion, six hundred fifty-seven million, three hundred twelve thousand, four hundred fifty-six".