91663992 has 48 divisors (see below), whose sum is σ = 283723440. Its totient is φ = 26189568.

The previous prime is 91663991. The next prime is 91663997. The reversal of 91663992 is 29936619.

It is a happy number.

91663992 is a `hidden beast` number, since 9 + 1 + 6 + 639 + 9 + 2 = 666.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91663991) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 90433 + ... + 91440.

It is an arithmetic number, because the mean of its divisors is an integer number (5910905).

Almost surely, 2^91663992 is an apocalyptic number.

It is an amenable number.

91663992 is an abundant number, since it is smaller than the sum of its proper divisors (192059448).

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

91663992 is a wasteful number, since it uses less digits than its factorization.

91663992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181892 (or 181885 counting only the distinct ones).

The product of its digits is 157464, while the sum is 45.

The square root of 91663992 is about 9574.1313966333. The cubic root of 91663992 is about 450.8854860743.

The spelling of 91663992 in words is "ninety-one million, six hundred sixty-three thousand, nine hundred ninety-two".