91990656 has 96 divisors (see below), whose sum is σ = 270504000. Its totient is φ = 29993472.

The previous prime is 91990651. The next prime is 91990673. The reversal of 91990656 is 65609919.

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (91990651) 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 11 ways as a sum of consecutive naturals, for example, 53295 + ... + 54993.

It is an arithmetic number, because the mean of its divisors is an integer number (2817750).

Almost surely, 2^91990656 is an apocalyptic number.

91990656 is a gapful number since it is divisible by the number (96) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91990656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135252000).

91990656 is an abundant number, since it is smaller than the sum of its proper divisors (178513344).

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

91990656 is a wasteful number, since it uses less digits than its factorization.

91990656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1766 (or 1751 counting only the distinct ones).

The product of its (nonzero) digits is 131220, while the sum is 45.

The square root of 91990656 is about 9591.1759445857. The cubic root of 91990656 is about 451.4204596401.

The spelling of 91990656 in words is "ninety-one million, nine hundred ninety thousand, six hundred fifty-six".