91318731 has 16 divisors (see below), whose sum is σ = 146476800. Its totient is φ = 49435488.

The previous prime is 91318687. The next prime is 91318739. The reversal of 91318731 is 13781319.

It is not a de Polignac number, because 91318731 - 2¹⁵ = 91285963 is a prime.

It is a super-2 number, since 2×91318731² = 16678221262900722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 91318692 and 91318701.

It is not an unprimeable number, because it can be changed into a prime (91318739) 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, 114036 + ... + 114833.

It is an arithmetic number, because the mean of its divisors is an integer number (9154800).

Almost surely, 2^91318731 is an apocalyptic number.

91318731 is a deficient number, since it is larger than the sum of its proper divisors (55158069).

91318731 is a wasteful number, since it uses less digits than its factorization.

91318731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228898.

The product of its digits is 4536, while the sum is 33.

The square root of 91318731 is about 9556.0834550563. The cubic root of 91318731 is about 450.3186730399.

The spelling of 91318731 in words is "ninety-one million, three hundred eighteen thousand, seven hundred thirty-one".