91972515 has 16 divisors (see below), whose sum is σ = 153554688. Its totient is φ = 46919136.

The previous prime is 91972513. The next prime is 91972537. The reversal of 91972515 is 51527919.

It is not a de Polignac number, because 91972515 - 2¹ = 91972513 is a prime.

It is a super-3 number, since 3×91972515³ (a number of 25 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (91972513) 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, 132949 + ... + 133638.

It is an arithmetic number, because the mean of its divisors is an integer number (9597168).

Almost surely, 2^91972515 is an apocalyptic number.

91972515 is a deficient number, since it is larger than the sum of its proper divisors (61582173).

91972515 is a wasteful number, since it uses less digits than its factorization.

91972515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 266618.

The product of its digits is 28350, while the sum is 39.

The square root of 91972515 is about 9590.2301849330. The cubic root of 91972515 is about 451.3907835937.

The spelling of 91972515 in words is "ninety-one million, nine hundred seventy-two thousand, five hundred fifteen".