816918864 has 80 divisors (see below), whose sum is σ = 2200811520. Its totient is φ = 260789760.

The previous prime is 816918847. The next prime is 816918871. The reversal of 816918864 is 468819618.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 174474 + ... + 179094.

It is an arithmetic number, because the mean of its divisors is an integer number (27510144).

Almost surely, 2^816918864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 816918864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1100405760).

816918864 is an abundant number, since it is smaller than the sum of its proper divisors (1383892656).

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

816918864 is a wasteful number, since it uses less digits than its factorization.

816918864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4788 (or 4782 counting only the distinct ones).

The product of its digits is 663552, while the sum is 51.

The square root of 816918864 is about 28581.7925260121. The cubic root of 816918864 is about 934.8163685627.

The spelling of 816918864 in words is "eight hundred sixteen million, nine hundred eighteen thousand, eight hundred sixty-four".