81996635320 has 32 divisors (see below), whose sum is σ = 187619425200. Its totient is φ = 32242743808.

The previous prime is 81996635317. The next prime is 81996635321. The reversal of 81996635320 is 2353669918.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81996635321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17369809 + ... + 17374528.

Almost surely, 2^81996635320 is an apocalyptic number.

It is an amenable number.

81996635320 is an abundant number, since it is smaller than the sum of its proper divisors (105622789880).

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

81996635320 is a wasteful number, since it uses less digits than its factorization.

81996635320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34744407 (or 34744403 counting only the distinct ones).

The product of its (nonzero) digits is 2099520, while the sum is 52.

The spelling of 81996635320 in words is "eighty-one billion, nine hundred ninety-six million, six hundred thirty-five thousand, three hundred twenty".