818779920 has 320 divisors, whose sum is σ = 3094087680. Its totient is φ = 174956544.

The previous prime is 818779909. The next prime is 818779961. The reversal of 818779920 is 29977818.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3606847 + ... + 3607073.

It is an arithmetic number, because the mean of its divisors is an integer number (9669024).

Almost surely, 2^818779920 is an apocalyptic number.

818779920 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 818779920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1547043840).

818779920 is an abundant number, since it is smaller than the sum of its proper divisors (2275307760).

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

818779920 is a wasteful number, since it uses less digits than its factorization.

818779920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 382 (or 376 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 51.

The square root of 818779920 is about 28614.3306753801. The cubic root of 818779920 is about 935.5257112034.

The spelling of 818779920 in words is "eight hundred eighteen million, seven hundred seventy-nine thousand, nine hundred twenty".