90915591 has 32 divisors (see below), whose sum is σ = 135976960. Its totient is φ = 53654400.

The previous prime is 90915577. The next prime is 90915611. The reversal of 90915591 is 19551909.

It is not a de Polignac number, because 90915591 - 2⁹ = 90915079 is a prime.

It is a super-3 number, since 3×90915591³ (a number of 25 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90915091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 167781 + ... + 168321.

It is an arithmetic number, because the mean of its divisors is an integer number (4249280).

Almost surely, 2^90915591 is an apocalyptic number.

90915591 is a deficient number, since it is larger than the sum of its proper divisors (45061369).

90915591 is a wasteful number, since it uses less digits than its factorization.

90915591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 727.

The product of its (nonzero) digits is 18225, while the sum is 39.

The square root of 90915591 is about 9534.9667540060. The cubic root of 90915591 is about 449.6550294399.

The spelling of 90915591 in words is "ninety million, nine hundred fifteen thousand, five hundred ninety-one".