91321507 has 2 divisors, whose sum is σ = 91321508. Its totient is φ = 91321506.

The previous prime is 91321499. The next prime is 91321519. The reversal of 91321507 is 70512319.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 91321507 - 2³ = 91321499 is a prime.

It is not a weakly prime, because it can be changed into another prime (91321547) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45660753 + 45660754.

It is an arithmetic number, because the mean of its divisors is an integer number (45660754).

Almost surely, 2^91321507 is an apocalyptic number.

91321507 is a deficient number, since it is larger than the sum of its proper divisors (1).

91321507 is an equidigital number, since it uses as much as digits as its factorization.

91321507 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1890, while the sum is 28.

The square root of 91321507 is about 9556.2287017421. The cubic root of 91321507 is about 450.3232360759.

The spelling of 91321507 in words is "ninety-one million, three hundred twenty-one thousand, five hundred seven".