99990720 has 224 divisors, whose sum is σ = 359907840. Its totient is φ = 26127360.

The previous prime is 99990703. The next prime is 99990731. The reversal of 99990720 is 2709999.

It is a super-2 number, since 2×99990720² = 19996288172236800, which contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 613359 + ... + 613521.

Almost surely, 2^99990720 is an apocalyptic number.

99990720 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 99990720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (179953920).

99990720 is an abundant number, since it is smaller than the sum of its proper divisors (259917120).

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

99990720 is a wasteful number, since it uses less digits than its factorization.

99990720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260 (or 244 counting only the distinct ones).

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

The square root of 99990720 is about 9999.5359892347. The cubic root of 99990720 is about 464.1445249357.

It can be divided in two parts, 999 and 90720, that added together give a palindrome (91719).

The spelling of 99990720 in words is "ninety-nine million, nine hundred ninety thousand, seven hundred twenty".