99721972 has 12 divisors (see below), whose sum is σ = 199444000. Its totient is φ = 42737976.

The previous prime is 99721969. The next prime is 99721987. The reversal of 99721972 is 27912799.

99721972 is an admirable number.

It is a hoax number, since the sum of its digits (46) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1780722 + ... + 1780777.

Almost surely, 2^99721972 is an apocalyptic number.

It is an amenable number.

99721972 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

99721972 is a wasteful number, since it uses less digits than its factorization.

99721972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3561510 (or 3561508 counting only the distinct ones).

The product of its digits is 142884, while the sum is 46.

The square root of 99721972 is about 9986.0889240984. The cubic root of 99721972 is about 463.7283201989.

The spelling of 99721972 in words is "ninety-nine million, seven hundred twenty-one thousand, nine hundred seventy-two".