816731136 has 264 divisors, whose sum is σ = 2695800744. Its totient is φ = 235929600.

The previous prime is 816731099. The next prime is 816731137. The reversal of 816731136 is 631137618.

It can be written as a sum of positive squares in 4 ways, for example, as 329204736 + 487526400 = 18144^2 + 22080^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 816731136.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (816731137) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2036536 + ... + 2036936.

Almost surely, 2^816731136 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 816731136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1347900372).

816731136 is an abundant number, since it is smaller than the sum of its proper divisors (1879069608).

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

816731136 is a wasteful number, since it uses less digits than its factorization.

816731136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 457 (or 436 counting only the distinct ones).

The product of its digits is 18144, while the sum is 36.

The square root of 816731136 is about 28578.5082885724. The cubic root of 816731136 is about 934.7447561259.

The spelling of 816731136 in words is "eight hundred sixteen million, seven hundred thirty-one thousand, one hundred thirty-six".