99740721 has 16 divisors (see below), whose sum is σ = 136454400. Its totient is φ = 64773888.

The previous prime is 99740713. The next prime is 99740723. The reversal of 99740721 is 12704799.

It is not a de Polignac number, because 99740721 - 2³ = 99740713 is a prime.

It is a super-2 number, since 2×99740721² = 19896422851199682, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 99740721.

It is not an unprimeable number, because it can be changed into a prime (99740723) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30745 + ... + 33833.

It is an arithmetic number, because the mean of its divisors is an integer number (8528400).

Almost surely, 2^99740721 is an apocalyptic number.

It is an amenable number.

99740721 is a deficient number, since it is larger than the sum of its proper divisors (36713679).

99740721 is a wasteful number, since it uses less digits than its factorization.

99740721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3368.

The product of its (nonzero) digits is 31752, while the sum is 39.

The square root of 99740721 is about 9987.0276358885. The cubic root of 99740721 is about 463.7573806533.

The spelling of 99740721 in words is "ninety-nine million, seven hundred forty thousand, seven hundred twenty-one".