56831991 has 8 divisors (see below), whose sum is σ = 75855984. Its totient is φ = 37848000.

The previous prime is 56831987. The next prime is 56832019. The reversal of 56831991 is 19913865.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 56831991 - 2² = 56831987 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56831981) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6510 + ... + 12491.

It is an arithmetic number, because the mean of its divisors is an integer number (9481998).

Almost surely, 2^56831991 is an apocalyptic number.

56831991 is a deficient number, since it is larger than the sum of its proper divisors (19023993).

56831991 is a wasteful number, since it uses less digits than its factorization.

56831991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20001.

The product of its digits is 58320, while the sum is 42.

The square root of 56831991 is about 7538.6995562895. The cubic root of 56831991 is about 384.4716224013.

The spelling of 56831991 in words is "fifty-six million, eight hundred thirty-one thousand, nine hundred ninety-one".