91520497 has 2 divisors, whose sum is σ = 91520498. Its totient is φ = 91520496.

The previous prime is 91520479. The next prime is 91520501. The reversal of 91520497 is 79402519.

Together with previous prime (91520479) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 84713616 + 6806881 = 9204^2 + 2609^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91520497 is a prime.

It is a super-2 number, since 2×91520497² = 16752002742254018, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (91520467) 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, 45760248 + 45760249.

It is an arithmetic number, because the mean of its divisors is an integer number (45760249).

Almost surely, 2^91520497 is an apocalyptic number.

It is an amenable number.

91520497 is a deficient number, since it is larger than the sum of its proper divisors (1).

91520497 is an equidigital number, since it uses as much as digits as its factorization.

91520497 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 22680, while the sum is 37.

The square root of 91520497 is about 9566.6345702133. The cubic root of 91520497 is about 450.6500842837.

It can be divided in two parts, 915 and 20497, that added together give a palindrome (21412).

The spelling of 91520497 in words is "ninety-one million, five hundred twenty thousand, four hundred ninety-seven".