91071089 has 2 divisors, whose sum is σ = 91071090. Its totient is φ = 91071088.

The previous prime is 91071037. The next prime is 91071143. The reversal of 91071089 is 98017019.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 62094400 + 28976689 = 7880^2 + 5383^2 .

It is a cyclic number.

It is not a de Polignac number, because 91071089 - 2²⁴ = 74293873 is a prime.

It is a Chen prime.

It is equal to p_5275538 and since 91071089 and 5275538 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (91071889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45535544 + 45535545.

It is an arithmetic number, because the mean of its divisors is an integer number (45535545).

Almost surely, 2^91071089 is an apocalyptic number.

It is an amenable number.

91071089 is a deficient number, since it is larger than the sum of its proper divisors (1).

91071089 is an equidigital number, since it uses as much as digits as its factorization.

91071089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4536, while the sum is 35.

The square root of 91071089 is about 9543.1173627908. The cubic root of 91071089 is about 449.9112401069.

The spelling of 91071089 in words is "ninety-one million, seventy-one thousand, eighty-nine".