816391536 has 20 divisors (see below), whose sum is σ = 2109011592. Its totient is φ = 272130496.

The previous prime is 816391523. The next prime is 816391553. The reversal of 816391536 is 635193618.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8504031 + ... + 8504126.

Almost surely, 2^816391536 is an apocalyptic number.

It is an amenable number.

816391536 is an abundant number, since it is smaller than the sum of its proper divisors (1292620056).

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

816391536 is a wasteful number, since it uses less digits than its factorization.

816391536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17008168 (or 17008162 counting only the distinct ones).

The product of its digits is 116640, while the sum is 42.

The square root of 816391536 is about 28572.5661430681. The cubic root of 816391536 is about 934.6151813234.

It can be divided in two parts, 8163 and 91536, that added together give a palindrome (99699).

The spelling of 816391536 in words is "eight hundred sixteen million, three hundred ninety-one thousand, five hundred thirty-six".