816231636 has 108 divisors (see below), whose sum is σ = 2366765856. Its totient is φ = 236559840.

The previous prime is 816231589. The next prime is 816231671. The reversal of 816231636 is 636132618.

816231636 is a `hidden beast` number, since 8 + 16 + 2 + 3 + 1 + 636 = 666.

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 816231636.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 96115 + ... + 104261.

Almost surely, 2^816231636 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 816231636, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1183382928).

816231636 is an abundant number, since it is smaller than the sum of its proper divisors (1550534220).

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

816231636 is a wasteful number, since it uses less digits than its factorization.

816231636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8202 (or 8186 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 816231636 is about 28569.7678674504. The cubic root of 816231636 is about 934.5541588365.

The spelling of 816231636 in words is "eight hundred sixteen million, two hundred thirty-one thousand, six hundred thirty-six".