816917920 has 192 divisors, whose sum is σ = 2501210880. Its totient is φ = 244850688.

The previous prime is 816917909. The next prime is 816917971. The reversal of 816917920 is 29719618.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 275164 + ... + 278116.

It is an arithmetic number, because the mean of its divisors is an integer number (13027140).

Almost surely, 2^816917920 is an apocalyptic number.

816917920 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 816917920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1250605440).

816917920 is an abundant number, since it is smaller than the sum of its proper divisors (1684292960).

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

816917920 is a wasteful number, since it uses less digits than its factorization.

816917920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3007 (or 2999 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 43.

The square root of 816917920 is about 28581.7760119976. The cubic root of 816917920 is about 934.8160084833.

The spelling of 816917920 in words is "eight hundred sixteen million, nine hundred seventeen thousand, nine hundred twenty".