56553966921 has 16 divisors (see below), whose sum is σ = 79679784960. Its totient is φ = 35606897040.

The previous prime is 56553966913. The next prime is 56553966947. The reversal of 56553966921 is 12966935565.

It is not a de Polignac number, because 56553966921 - 2³ = 56553966913 is a prime.

It is not an unprimeable number, because it can be changed into a prime (56553966991) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5182035 + ... + 5192936.

It is an arithmetic number, because the mean of its divisors is an integer number (4979986560).

Almost surely, 2^56553966921 is an apocalyptic number.

It is an amenable number.

56553966921 is a deficient number, since it is larger than the sum of its proper divisors (23125818039).

56553966921 is a wasteful number, since it uses less digits than its factorization.

56553966921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10375076.

The product of its digits is 13122000, while the sum is 57.

The spelling of 56553966921 in words is "fifty-six billion, five hundred fifty-three million, nine hundred sixty-six thousand, nine hundred twenty-one".