921247664 has 20 divisors (see below), whose sum is σ = 1802592960. Its totient is φ = 456062400.

The previous prime is 921247619. The next prime is 921247687. The reversal of 921247664 is 466742129.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 283424 + ... + 286655.

It is an arithmetic number, because the mean of its divisors is an integer number (90129648).

Almost surely, 2^921247664 is an apocalyptic number.

It is an amenable number.

921247664 is a deficient number, since it is larger than the sum of its proper divisors (881345296).

921247664 is a wasteful number, since it uses less digits than its factorization.

921247664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 570188 (or 570182 counting only the distinct ones).

The product of its digits is 145152, while the sum is 41.

The square root of 921247664 is about 30352.0619398419. The cubic root of 921247664 is about 973.0282885120.

The spelling of 921247664 in words is "nine hundred twenty-one million, two hundred forty-seven thousand, six hundred sixty-four".