56439921 has 4 divisors (see below), whose sum is σ = 75253232. Its totient is φ = 37626612.

The previous prime is 56439893. The next prime is 56439941. The reversal of 56439921 is 12993465.

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 56439921 - 2⁷ = 56439793 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 56439921.

It is not an unprimeable number, because it can be changed into a prime (56439941) 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, 9406651 + ... + 9406656.

It is an arithmetic number, because the mean of its divisors is an integer number (18813308).

Almost surely, 2^56439921 is an apocalyptic number.

It is an amenable number.

56439921 is a deficient number, since it is larger than the sum of its proper divisors (18813311).

56439921 is a wasteful number, since it uses less digits than its factorization.

56439921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18813310.

The product of its digits is 58320, while the sum is 39.

The square root of 56439921 is about 7512.6507306010. The cubic root of 56439921 is about 383.5854562356.

The spelling of 56439921 in words is "fifty-six million, four hundred thirty-nine thousand, nine hundred twenty-one".