91628815 has 4 divisors (see below), whose sum is σ = 109954584. Its totient is φ = 73303048.

The previous prime is 91628783. The next prime is 91628833. The reversal of 91628815 is 51882619.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 91628815 - 2⁵ = 91628783 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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 3 ways as a sum of consecutive naturals, for example, 9162877 + ... + 9162886.

It is an arithmetic number, because the mean of its divisors is an integer number (27488646).

Almost surely, 2^91628815 is an apocalyptic number.

91628815 is a deficient number, since it is larger than the sum of its proper divisors (18325769).

91628815 is a wasteful number, since it uses less digits than its factorization.

91628815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18325768.

The product of its digits is 34560, while the sum is 40.

The square root of 91628815 is about 9572.2941346367. The cubic root of 91628815 is about 450.8278013800.

The spelling of 91628815 in words is "ninety-one million, six hundred twenty-eight thousand, eight hundred fifteen".