91664497 has 2 divisors, whose sum is σ = 91664498. Its totient is φ = 91664496.

The previous prime is 91664491. The next prime is 91664543. The reversal of 91664497 is 79446619.

It is an a-pointer prime, because the next prime (91664543) can be obtained adding 91664497 to its sum of digits (46).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 88811776 + 2852721 = 9424^2 + 1689^2 .

It is a cyclic number.

It is not a de Polignac number, because 91664497 - 2⁷ = 91664369 is a prime.

It is not a weakly prime, because it can be changed into another prime (91664491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45832248 + 45832249.

It is an arithmetic number, because the mean of its divisors is an integer number (45832249).

Almost surely, 2^91664497 is an apocalyptic number.

It is an amenable number.

91664497 is a deficient number, since it is larger than the sum of its proper divisors (1).

91664497 is an equidigital number, since it uses as much as digits as its factorization.

91664497 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 46.

The square root of 91664497 is about 9574.1577697466. The cubic root of 91664497 is about 450.8863140867.

The spelling of 91664497 in words is "ninety-one million, six hundred sixty-four thousand, four hundred ninety-seven".