56981791 has 2 divisors, whose sum is σ = 56981792. Its totient is φ = 56981790.

The previous prime is 56981713. The next prime is 56981849. The reversal of 56981791 is 19718965.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-56981791 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56981711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28490895 + 28490896.

It is an arithmetic number, because the mean of its divisors is an integer number (28490896).

Almost surely, 2^56981791 is an apocalyptic number.

56981791 is a deficient number, since it is larger than the sum of its proper divisors (1).

56981791 is an equidigital number, since it uses as much as digits as its factorization.

56981791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 136080, while the sum is 46.

The square root of 56981791 is about 7548.6284184612. The cubic root of 56981791 is about 384.8091278525.

The spelling of 56981791 in words is "fifty-six million, nine hundred eighty-one thousand, seven hundred ninety-one".