56921687 has 2 divisors, whose sum is σ = 56921688. Its totient is φ = 56921686.

The previous prime is 56921621. The next prime is 56921699. The reversal of 56921687 is 78612965.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 56921687 - 2¹² = 56917591 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56921617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28460843 + 28460844.

It is an arithmetic number, because the mean of its divisors is an integer number (28460844).

Almost surely, 2^56921687 is an apocalyptic number.

56921687 is a deficient number, since it is larger than the sum of its proper divisors (1).

56921687 is an equidigital number, since it uses as much as digits as its factorization.

56921687 is an evil number, because the sum of its binary digits is even.

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

The square root of 56921687 is about 7544.6462475056. The cubic root of 56921687 is about 384.6737822497.

The spelling of 56921687 in words is "fifty-six million, nine hundred twenty-one thousand, six hundred eighty-seven".