90091915 has 4 divisors (see below), whose sum is σ = 108110304. Its totient is φ = 72073528.

The previous prime is 90091867. The next prime is 90091927. The reversal of 90091915 is 51919009.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 51919009 = 1621 ⋅32029.

It is a cyclic number.

It is not a de Polignac number, because 90091915 - 2¹⁹ = 89567627 is a prime.

It is a Duffinian 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, 9009187 + ... + 9009196.

It is an arithmetic number, because the mean of its divisors is an integer number (27027576).

Almost surely, 2^90091915 is an apocalyptic number.

90091915 is a deficient number, since it is larger than the sum of its proper divisors (18018389).

90091915 is a wasteful number, since it uses less digits than its factorization.

90091915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18018388.

The product of its (nonzero) digits is 3645, while the sum is 34.

The square root of 90091915 is about 9491.6760901329. The cubic root of 90091915 is about 448.2929813863.

The spelling of 90091915 in words is "ninety million, ninety-one thousand, nine hundred fifteen".