91613879 has 12 divisors (see below), whose sum is σ = 107088408. Its totient is φ = 78145200.

The previous prime is 91613869. The next prime is 91613909. The reversal of 91613879 is 97831619.

It is not a de Polignac number, because 91613879 - 2¹² = 91609783 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91613869) 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, 5909 + ... + 14769.

It is an arithmetic number, because the mean of its divisors is an integer number (8924034).

Almost surely, 2^91613879 is an apocalyptic number.

91613879 is a deficient number, since it is larger than the sum of its proper divisors (15474529).

91613879 is a wasteful number, since it uses less digits than its factorization.

91613879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9086 (or 9079 counting only the distinct ones).

The product of its digits is 81648, while the sum is 44.

The square root of 91613879 is about 9571.5139345874. The cubic root of 91613879 is about 450.8033042464.

The spelling of 91613879 in words is "ninety-one million, six hundred thirteen thousand, eight hundred seventy-nine".