91172139 has 16 divisors (see below), whose sum is σ = 129576960. Its totient is φ = 56822400.

The previous prime is 91172119. The next prime is 91172153. The reversal of 91172139 is 93127119.

It is not a de Polignac number, because 91172139 - 2¹² = 91168043 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91172119) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1782 + ... + 13620.

It is an arithmetic number, because the mean of its divisors is an integer number (8098560).

Almost surely, 2^91172139 is an apocalyptic number.

91172139 is a deficient number, since it is larger than the sum of its proper divisors (38404821).

91172139 is a wasteful number, since it uses less digits than its factorization.

91172139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12010.

The product of its digits is 3402, while the sum is 33.

The square root of 91172139 is about 9548.4102865346. The cubic root of 91172139 is about 450.0775816856.

The spelling of 91172139 in words is "ninety-one million, one hundred seventy-two thousand, one hundred thirty-nine".