56191686591 has 16 divisors (see below), whose sum is σ = 78873136640. Its totient is φ = 35486061120.

The previous prime is 56191686583. The next prime is 56191686599. The reversal of 56191686591 is 19568619165.

It is an interprime number because it is at equal distance from previous prime (56191686583) and next prime (56191686599).

It is not a de Polignac number, because 56191686591 - 2³ = 56191686583 is a prime.

It is a super-3 number, since 3×56191686591³ (a number of 33 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56191686599) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 632826 + ... + 716136.

It is an arithmetic number, because the mean of its divisors is an integer number (4929571040).

Almost surely, 2^56191686591 is an apocalyptic number.

56191686591 is a deficient number, since it is larger than the sum of its proper divisors (22681450049).

56191686591 is a wasteful number, since it uses less digits than its factorization.

56191686591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95166.

The product of its digits is 3499200, while the sum is 57.

The spelling of 56191686591 in words is "fifty-six billion, one hundred ninety-one million, six hundred eighty-six thousand, five hundred ninety-one".