56639989 has 4 divisors (see below), whose sum is σ = 64731424. Its totient is φ = 48548556.

The previous prime is 56639981. The next prime is 56640011. The reversal of 56639989 is 98993665.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 56639989 - 2³ = 56639981 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56639981) 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, 4045707 + ... + 4045720.

It is an arithmetic number, because the mean of its divisors is an integer number (16182856).

Almost surely, 2^56639989 is an apocalyptic number.

It is an amenable number.

56639989 is a deficient number, since it is larger than the sum of its proper divisors (8091435).

56639989 is an equidigital number, since it uses as much as digits as its factorization.

56639989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8091434.

The product of its digits is 3149280, while the sum is 55.

The square root of 56639989 is about 7525.9543580864. The cubic root of 56639989 is about 384.0381657848.

The spelling of 56639989 in words is "fifty-six million, six hundred thirty-nine thousand, nine hundred eighty-nine".