91572731 has 2 divisors, whose sum is σ = 91572732. Its totient is φ = 91572730.

The previous prime is 91572713. The next prime is 91572737. The reversal of 91572731 is 13727519.

It is a happy number.

Together with previous prime (91572713) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 91572731 - 2²² = 87378427 is a prime.

It is a super-2 number, since 2×91572731² = 16771130125596722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 91572691 and 91572700.

It is not a weakly prime, because it can be changed into another prime (91572737) 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 as a sum of consecutive naturals, namely, 45786365 + 45786366.

It is an arithmetic number, because the mean of its divisors is an integer number (45786366).

Almost surely, 2^91572731 is an apocalyptic number.

91572731 is a deficient number, since it is larger than the sum of its proper divisors (1).

91572731 is an equidigital number, since it uses as much as digits as its factorization.

91572731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13230, while the sum is 35.

The square root of 91572731 is about 9569.3641899554. The cubic root of 91572731 is about 450.7358019843.

The spelling of 91572731 in words is "ninety-one million, five hundred seventy-two thousand, seven hundred thirty-one".