91307889 has 12 divisors (see below), whose sum is σ = 133696836. Its totient is φ = 60037632.

The previous prime is 91307857. The next prime is 91307891. The reversal of 91307889 is 98870319.

91307889 = T₁₅₄₅ + T₁₅₄₆ + ... + T₁₆₁₇.

It can be written as a sum of positive squares in 2 ways, for example, as 17640000 + 73667889 = 4200^2 + 8583^2 .

It is not a de Polignac number, because 91307889 - 2⁵ = 91307857 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91307809) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 68832 + ... + 70145.

It is an arithmetic number, because the mean of its divisors is an integer number (11141403).

Almost surely, 2^91307889 is an apocalyptic number.

It is an amenable number.

91307889 is a deficient number, since it is larger than the sum of its proper divisors (42388947).

91307889 is a wasteful number, since it uses less digits than its factorization.

91307889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139056 (or 139053 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 45.

The square root of 91307889 is about 9555.5161556035. The cubic root of 91307889 is about 450.3008506712.

The spelling of 91307889 in words is "ninety-one million, three hundred seven thousand, eight hundred eighty-nine".