816321056 has 48 divisors (see below), whose sum is σ = 1630601280. Its totient is φ = 402243840.

The previous prime is 816321043. The next prime is 816321059. The reversal of 816321056 is 650123618.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (816321059) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 791261 + ... + 792291.

It is an arithmetic number, because the mean of its divisors is an integer number (33970860).

Almost surely, 2^816321056 is an apocalyptic number.

816321056 is the 16496-th octagonal number.

It is an amenable number.

816321056 is a deficient number, since it is larger than the sum of its proper divisors (814280224).

816321056 is a wasteful number, since it uses less digits than its factorization.

816321056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1377 (or 1369 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 816321056 is about 28571.3327655537. The cubic root of 816321056 is about 934.5882850893.

The spelling of 816321056 in words is "eight hundred sixteen million, three hundred twenty-one thousand, fifty-six".