91915631 has 8 divisors (see below), whose sum is σ = 93649920. Its totient is φ = 90195768.

The previous prime is 91915591. The next prime is 91915657. The reversal of 91915631 is 13651919.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91915631 is a prime.

It is a super-2 number, since 2×91915631² = 16896966444256322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 91915591 and 91915600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91915661) 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, 9710 + ... + 16676.

It is an arithmetic number, because the mean of its divisors is an integer number (11706240).

Almost surely, 2^91915631 is an apocalyptic number.

91915631 is a deficient number, since it is larger than the sum of its proper divisors (1734289).

91915631 is a wasteful number, since it uses less digits than its factorization.

91915631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7213.

The product of its digits is 7290, while the sum is 35.

The square root of 91915631 is about 9587.2639997029. The cubic root of 91915631 is about 451.2977043052.

The spelling of 91915631 in words is "ninety-one million, nine hundred fifteen thousand, six hundred thirty-one".