91872815 has 8 divisors (see below), whose sum is σ = 110706288. Its totient is φ = 73192320.

The previous prime is 91872791. The next prime is 91872829. The reversal of 91872815 is 51827819.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 91872815 - 2⁸ = 91872559 is a prime.

It is a super-2 number, since 2×91872815² = 16881228272048450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36917 + ... + 39326.

It is an arithmetic number, because the mean of its divisors is an integer number (13838286).

Almost surely, 2^91872815 is an apocalyptic number.

91872815 is a deficient number, since it is larger than the sum of its proper divisors (18833473).

91872815 is a wasteful number, since it uses less digits than its factorization.

91872815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76489.

The product of its digits is 40320, while the sum is 41.

The square root of 91872815 is about 9585.0307772067. The cubic root of 91872815 is about 451.2276191507.

The spelling of 91872815 in words is "ninety-one million, eight hundred seventy-two thousand, eight hundred fifteen".