81634996432 has 30 divisors (see below), whose sum is σ = 173853873074. Its totient is φ = 37106815680.

The previous prime is 81634996423. The next prime is 81634996453. The reversal of 81634996432 is 23469943618.

It can be written as a sum of positive squares in only one way, i.e., 46977961536 + 34657034896 = 216744^2 + 186164^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 21081483 + ... + 21085354.

Almost surely, 2^81634996432 is an apocalyptic number.

It is an amenable number.

81634996432 is an abundant number, since it is smaller than the sum of its proper divisors (92218876642).

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

81634996432 is a wasteful number, since it uses less digits than its factorization.

81634996432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42166867 (or 42166850 counting only the distinct ones).

The product of its digits is 6718464, while the sum is 55.

The spelling of 81634996432 in words is "eighty-one billion, six hundred thirty-four million, nine hundred ninety-six thousand, four hundred thirty-two".