6556533921 has 12 divisors (see below), whose sum is σ = 10823484672. Its totient is φ = 3746590776.

The previous prime is 6556533913. The next prime is 6556533931. The reversal of 6556533921 is 1293356556.

6556533921 is a `hidden beast` number, since 6 + 556 + 5 + 3 + 3 + 92 + 1 = 666.

It is not a de Polignac number, because 6556533921 - 2³ = 6556533913 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (6556533931) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 52035921 + ... + 52036046.

It is an arithmetic number, because the mean of its divisors is an integer number (901957056).

Almost surely, 2^6556533921 is an apocalyptic number.

It is an amenable number.

6556533921 is a deficient number, since it is larger than the sum of its proper divisors (4266950751).

6556533921 is a wasteful number, since it uses less digits than its factorization.

6556533921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104071980 (or 104071977 counting only the distinct ones).

The product of its digits is 729000, while the sum is 45.

The square root of 6556533921 is about 80972.4269180565. The cubic root of 6556533921 is about 1871.6505698121.

The spelling of 6556533921 in words is "six billion, five hundred fifty-six million, five hundred thirty-three thousand, nine hundred twenty-one".