56973991 has 2 divisors, whose sum is σ = 56973992. Its totient is φ = 56973990.

The previous prime is 56973979. The next prime is 56973997. The reversal of 56973991 is 19937965.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 56973991 - 2⁷ = 56973863 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56973997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28486995 + 28486996.

It is an arithmetic number, because the mean of its divisors is an integer number (28486996).

Almost surely, 2^56973991 is an apocalyptic number.

56973991 is a deficient number, since it is larger than the sum of its proper divisors (1).

56973991 is an equidigital number, since it uses as much as digits as its factorization.

56973991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 459270, while the sum is 49.

The square root of 56973991 is about 7548.1117506301. Note that the first 3 decimals coincide. The cubic root of 56973991 is about 384.7915687451.

The spelling of 56973991 in words is "fifty-six million, nine hundred seventy-three thousand, nine hundred ninety-one".