997921997408 has 24 divisors (see below), whose sum is σ = 2245324494672. Its totient is φ = 427680855936.

The previous prime is 997921997399. The next prime is 997921997431. The reversal of 997921997408 is 804799129799.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2227504235 + ... + 2227504682.

It is an arithmetic number, because the mean of its divisors is an integer number (93555187278).

Almost surely, 2^997921997408 is an apocalyptic number.

It is an amenable number.

997921997408 is an abundant number, since it is smaller than the sum of its proper divisors (1247402497264).

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

997921997408 is a wasteful number, since it uses less digits than its factorization.

997921997408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4455008934 (or 4455008926 counting only the distinct ones).

The product of its (nonzero) digits is 185177664, while the sum is 74.

The spelling of 997921997408 in words is "nine hundred ninety-seven billion, nine hundred twenty-one million, nine hundred ninety-seven thousand, four hundred eight".