91990015 has 8 divisors (see below), whose sum is σ = 118879488. Its totient is φ = 67931040.

The previous prime is 91990007. The next prime is 91990081. The reversal of 91990015 is 51009919.

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

It is not a de Polignac number, because 91990015 - 2³ = 91990007 is a prime.

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, 707551 + ... + 707680.

It is an arithmetic number, because the mean of its divisors is an integer number (14859936).

Almost surely, 2^91990015 is an apocalyptic number.

91990015 is a deficient number, since it is larger than the sum of its proper divisors (26889473).

91990015 is a wasteful number, since it uses less digits than its factorization.

91990015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1415249.

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

The square root of 91990015 is about 9591.1425283957. The cubic root of 91990015 is about 451.4194111236.

The spelling of 91990015 in words is "ninety-one million, nine hundred ninety thousand, fifteen".