91057856831 has 8 divisors (see below), whose sum is σ = 91793500944. Its totient is φ = 90324933120.

The previous prime is 91057856761. The next prime is 91057856849. The reversal of 91057856831 is 13865875019.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 91057856831 - 2²² = 91053662527 is a prime.

It is a super-2 number, since 2×91057856831² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91057856861) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 612860 + ... + 746801.

It is an arithmetic number, because the mean of its divisors is an integer number (11474187618).

Almost surely, 2^91057856831 is an apocalyptic number.

91057856831 is a deficient number, since it is larger than the sum of its proper divisors (735644113).

91057856831 is a wasteful number, since it uses less digits than its factorization.

91057856831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1360201.

The product of its (nonzero) digits is 1814400, while the sum is 53.

The spelling of 91057856831 in words is "ninety-one billion, fifty-seven million, eight hundred fifty-six thousand, eight hundred thirty-one".