99731920 has 40 divisors (see below), whose sum is σ = 232440480. Its totient is φ = 39795840.

The previous prime is 99731903. The next prime is 99731939. The reversal of 99731920 is 2913799.

It is a tau number, because it is divible by the number of its divisors (40).

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38011 + ... + 40549.

It is an arithmetic number, because the mean of its divisors is an integer number (5811012).

Almost surely, 2^99731920 is an apocalyptic number.

It is an amenable number.

99731920 is an abundant number, since it is smaller than the sum of its proper divisors (132708560).

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

99731920 is a wasteful number, since it uses less digits than its factorization.

99731920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3043 (or 3037 counting only the distinct ones).

The product of its (nonzero) digits is 30618, while the sum is 40.

The square root of 99731920 is about 9986.5870045777. The cubic root of 99731920 is about 463.7437397895.

The spelling of 99731920 in words is "ninety-nine million, seven hundred thirty-one thousand, nine hundred twenty".