81722639232 has 160 divisors (see below), whose sum is σ = 261913778280. Its totient is φ = 25145385984.

The previous prime is 81722639227. The next prime is 81722639249. The reversal of 81722639232 is 23293622718.

81722639232 is a `hidden beast` number, since 8 + 1 + 7 + 2 + 2 + 639 + 2 + 3 + 2 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 168378 + ... + 437945.

Almost surely, 2^81722639232 is an apocalyptic number.

It is an amenable number.

81722639232 is an abundant number, since it is smaller than the sum of its proper divisors (180191139048).

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

81722639232 is a wasteful number, since it uses less digits than its factorization.

81722639232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 606362 (or 606341 counting only the distinct ones).

The product of its digits is 435456, while the sum is 45.

The spelling of 81722639232 in words is "eighty-one billion, seven hundred twenty-two million, six hundred thirty-nine thousand, two hundred thirty-two".