56965081991 has 4 divisors (see below), whose sum is σ = 57150636312. Its totient is φ = 56779527672.

The previous prime is 56965081967. The next prime is 56965081993. The reversal of 56965081991 is 19918056965.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 56965081991 - 2¹⁴ = 56965065607 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 56965081991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56965081993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 92776700 + ... + 92777313.

It is an arithmetic number, because the mean of its divisors is an integer number (14287659078).

Almost surely, 2^56965081991 is an apocalyptic number.

56965081991 is a deficient number, since it is larger than the sum of its proper divisors (185554321).

56965081991 is a wasteful number, since it uses less digits than its factorization.

56965081991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185554320.

The product of its (nonzero) digits is 5248800, while the sum is 59.

The spelling of 56965081991 in words is "fifty-six billion, nine hundred sixty-five million, eighty-one thousand, nine hundred ninety-one".