91521697 has 2 divisors, whose sum is σ = 91521698. Its totient is φ = 91521696.

The previous prime is 91521691. The next prime is 91521707. The reversal of 91521697 is 79612519.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50253921 + 41267776 = 7089^2 + 6424^2 .

It is a cyclic number.

It is not a de Polignac number, because 91521697 - 2⁷ = 91521569 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (91521691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45760848 + 45760849.

It is an arithmetic number, because the mean of its divisors is an integer number (45760849).

Almost surely, 2^91521697 is an apocalyptic number.

It is an amenable number.

91521697 is a deficient number, since it is larger than the sum of its proper divisors (1).

91521697 is an equidigital number, since it uses as much as digits as its factorization.

91521697 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34020, while the sum is 40.

The square root of 91521697 is about 9566.6972879882. The cubic root of 91521697 is about 450.6520538889.

The spelling of 91521697 in words is "ninety-one million, five hundred twenty-one thousand, six hundred ninety-seven".