56438991 has 32 divisors (see below), whose sum is σ = 97006080. Its totient is φ = 31762368.

The previous prime is 56438989. The next prime is 56439007. The reversal of 56438991 is 19983465.

It is a happy number.

56438991 is a `hidden beast` number, since 564 + 3 + 89 + 9 + 1 = 666.

It is not a de Polignac number, because 56438991 - 2¹ = 56438989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56438971) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10435 + ... + 14891.

It is an arithmetic number, because the mean of its divisors is an integer number (3031440).

Almost surely, 2^56438991 is an apocalyptic number.

56438991 is a deficient number, since it is larger than the sum of its proper divisors (40567089).

56438991 is a wasteful number, since it uses less digits than its factorization.

56438991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4540 (or 4534 counting only the distinct ones).

The product of its digits is 233280, while the sum is 45.

The square root of 56438991 is about 7512.5888347493. The cubic root of 56438991 is about 383.5833493555.

The spelling of 56438991 in words is "fifty-six million, four hundred thirty-eight thousand, nine hundred ninety-one".