91990368 has 36 divisors (see below), whose sum is σ = 261598428. Its totient is φ = 30663360.

The previous prime is 91990321. The next prime is 91990411. The reversal of 91990368 is 86309919.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-3 number, since 3×91990368³ (a number of 25 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 159418 + ... + 159993.

It is an arithmetic number, because the mean of its divisors is an integer number (7266623).

Almost surely, 2^91990368 is an apocalyptic number.

It is an amenable number.

91990368 is an abundant number, since it is smaller than the sum of its proper divisors (169608060).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91990368 is a wasteful number, since it uses less digits than its factorization.

91990368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 319427 (or 319416 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 45.

The square root of 91990368 is about 9591.1609307737. The cubic root of 91990368 is about 451.4199885444.

The spelling of 91990368 in words is "ninety-one million, nine hundred ninety thousand, three hundred sixty-eight".