97920921 has 16 divisors (see below), whose sum is σ = 151660928. Its totient is φ = 55036800.

The previous prime is 97920883. The next prime is 97920923. The reversal of 97920921 is 12902979.

It is a happy number.

It is not a de Polignac number, because 97920921 - 2⁷ = 97920793 is a prime.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is the 9896-th Hogben number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 97920921.

It is not an unprimeable number, because it can be changed into a prime (97920923) by changing a digit.

It is a nontrivial repunit in base 9895.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36940 + ... + 39501.

It is an arithmetic number, because the mean of its divisors is an integer number (9478808).

Almost surely, 2^97920921 is an apocalyptic number.

It is an amenable number.

97920921 is a deficient number, since it is larger than the sum of its proper divisors (53740007).

97920921 is a wasteful number, since it uses less digits than its factorization.

97920921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76512.

The product of its (nonzero) digits is 20412, while the sum is 39.

The square root of 97920921 is about 9895.5000378960. The cubic root of 97920921 is about 460.9195860762.

The spelling of 97920921 in words is "ninety-seven million, nine hundred twenty thousand, nine hundred twenty-one".