99907920 has 240 divisors, whose sum is σ = 393224832. Its totient is φ = 22256640.

The previous prime is 99907919. The next prime is 99907937. The reversal of 99907920 is 2970999.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 216490 + ... + 216950.

Almost surely, 2^99907920 is an apocalyptic number.

99907920 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 99907920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (196612416).

99907920 is an abundant number, since it is smaller than the sum of its proper divisors (293316912).

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

99907920 is a wasteful number, since it uses less digits than its factorization.

99907920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 530 (or 521 counting only the distinct ones).

The product of its (nonzero) digits is 91854, while the sum is 45.

The square root of 99907920 is about 9995.3949396710. The cubic root of 99907920 is about 464.0163737781.

The spelling of 99907920 in words is "ninety-nine million, nine hundred seven thousand, nine hundred twenty".