91571213 has 2 divisors, whose sum is σ = 91571214. Its totient is φ = 91571212.

The previous prime is 91571173. The next prime is 91571251. The reversal of 91571213 is 31217519.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55547209 + 36024004 = 7453^2 + 6002^2 .

It is a cyclic number.

It is not a de Polignac number, because 91571213 - 2⁸ = 91570957 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91561213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45785606 + 45785607.

It is an arithmetic number, because the mean of its divisors is an integer number (45785607).

Almost surely, 2^91571213 is an apocalyptic number.

It is an amenable number.

91571213 is a deficient number, since it is larger than the sum of its proper divisors (1).

91571213 is an equidigital number, since it uses as much as digits as its factorization.

91571213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1890, while the sum is 29.

The square root of 91571213 is about 9569.2848740123. The cubic root of 91571213 is about 450.7333113567.

The spelling of 91571213 in words is "ninety-one million, five hundred seventy-one thousand, two hundred thirteen".