99639972 has 36 divisors (see below), whose sum is σ = 252894096. Its totient is φ = 33078000.

The previous prime is 99639959. The next prime is 99640007. The reversal of 99639972 is 27993699.

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

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3523 + ... + 14549.

It is an arithmetic number, because the mean of its divisors is an integer number (7024836).

Almost surely, 2^99639972 is an apocalyptic number.

It is an amenable number.

99639972 is an abundant number, since it is smaller than the sum of its proper divisors (153254124).

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

99639972 is a wasteful number, since it uses less digits than its factorization.

99639972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11288 (or 11283 counting only the distinct ones).

The product of its digits is 1653372, while the sum is 54.

The square root of 99639972 is about 9981.9823682473. The cubic root of 99639972 is about 463.6011795467.

The spelling of 99639972 in words is "ninety-nine million, six hundred thirty-nine thousand, nine hundred seventy-two".