91288015 has 32 divisors (see below), whose sum is σ = 135467136. Its totient is φ = 57507840.

The previous prime is 91288009. The next prime is 91288019. The reversal of 91288015 is 51088219.

It is not a de Polignac number, because 91288015 - 2¹⁷ = 91156943 is a prime.

It is a Smith number, since the sum of its digits (34) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91288019) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 142095 + ... + 142735.

It is an arithmetic number, because the mean of its divisors is an integer number (4233348).

Almost surely, 2^91288015 is an apocalyptic number.

91288015 is a deficient number, since it is larger than the sum of its proper divisors (44179121).

91288015 is a wasteful number, since it uses less digits than its factorization.

91288015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 979.

The product of its (nonzero) digits is 5760, while the sum is 34.

The square root of 91288015 is about 9554.4761761177. The cubic root of 91288015 is about 450.2681775963.

The spelling of 91288015 in words is "ninety-one million, two hundred eighty-eight thousand, fifteen".