816991132 has 18 divisors (see below), whose sum is σ = 1480741808. Its totient is φ = 394407888.

The previous prime is 816991129. The next prime is 816991139. The reversal of 816991132 is 231199618.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (816991139) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 118068 + ... + 124795.

Almost surely, 2^816991132 is an apocalyptic number.

It is an amenable number.

816991132 is a deficient number, since it is larger than the sum of its proper divisors (663750676).

816991132 is a wasteful number, since it uses less digits than its factorization.

816991132 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242925 (or 242894 counting only the distinct ones).

The product of its digits is 23328, while the sum is 40.

The square root of 816991132 is about 28583.0567294682. The cubic root of 816991132 is about 934.8439336491.

The spelling of 816991132 in words is "eight hundred sixteen million, nine hundred ninety-one thousand, one hundred thirty-two".