97215921 has 12 divisors (see below), whose sum is σ = 153188880. Its totient is φ = 58918680.

The previous prime is 97215889. The next prime is 97215941. The reversal of 97215921 is 12951279.

It is not a de Polignac number, because 97215921 - 2⁵ = 97215889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (97215941) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 490891 + ... + 491088.

It is an arithmetic number, because the mean of its divisors is an integer number (12765740).

Almost surely, 2^97215921 is an apocalyptic number.

It is an amenable number.

97215921 is a deficient number, since it is larger than the sum of its proper divisors (55972959).

97215921 is a wasteful number, since it uses less digits than its factorization.

97215921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 981996 (or 981993 counting only the distinct ones).

The product of its digits is 11340, while the sum is 36.

The square root of 97215921 is about 9859.8134363689. The cubic root of 97215921 is about 459.8107617950.

The spelling of 97215921 in words is "ninety-seven million, two hundred fifteen thousand, nine hundred twenty-one".