91639932 has 12 divisors (see below), whose sum is σ = 213826536. Its totient is φ = 30546640.

The previous prime is 91639927. The next prime is 91639939. The reversal of 91639932 is 23993619.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91639939) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3818319 + ... + 3818342.

It is an arithmetic number, because the mean of its divisors is an integer number (17818878).

Almost surely, 2^91639932 is an apocalyptic number.

It is an amenable number.

91639932 is an abundant number, since it is smaller than the sum of its proper divisors (122186604).

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

91639932 is a wasteful number, since it uses less digits than its factorization.

91639932 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7636668 (or 7636666 counting only the distinct ones).

The product of its digits is 78732, while the sum is 42.

The square root of 91639932 is about 9572.8748033180. The cubic root of 91639932 is about 450.8460330901.

The spelling of 91639932 in words is "ninety-one million, six hundred thirty-nine thousand, nine hundred thirty-two".