56687921 has 8 divisors (see below), whose sum is σ = 57558144. Its totient is φ = 55822320.

The previous prime is 56687903. The next prime is 56687923. The reversal of 56687921 is 12978665.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-56687921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (56687923) 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, 29531 + ... + 31391.

It is an arithmetic number, because the mean of its divisors is an integer number (7194768).

Almost surely, 2^56687921 is an apocalyptic number.

It is an amenable number.

56687921 is a deficient number, since it is larger than the sum of its proper divisors (870223).

56687921 is a wasteful number, since it uses less digits than its factorization.

56687921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2311.

The product of its digits is 181440, while the sum is 44.

The square root of 56687921 is about 7529.1381312870. The cubic root of 56687921 is about 384.1464669314.

The spelling of 56687921 in words is "fifty-six million, six hundred eighty-seven thousand, nine hundred twenty-one".