816338923920 has 560 divisors, whose sum is σ = 3147513306672. Its totient is φ = 195507302400.

The previous prime is 816338923919. The next prime is 816338923931. The reversal of 816338923920 is 29329833618.

It is a happy number.

816338923920 is a `hidden beast` number, since 8 + 1 + 6 + 3 + 389 + 239 + 20 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 115589120256 + 700749803664 = 339984^2 + 837108^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 28037370 + ... + 28066470.

Almost surely, 2^816338923920 is an apocalyptic number.

816338923920 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 816338923920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1573756653336).

816338923920 is an abundant number, since it is smaller than the sum of its proper divisors (2331174382752).

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

816338923920 is a wasteful number, since it uses less digits than its factorization.

816338923920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29182 (or 29161 counting only the distinct ones).

The product of its (nonzero) digits is 3359232, while the sum is 54.

The spelling of 816338923920 in words is "eight hundred sixteen billion, three hundred thirty-eight million, nine hundred twenty-three thousand, nine hundred twenty".