81323239192 has 32 divisors (see below), whose sum is σ = 164353049280. Its totient is φ = 37501194240.

The previous prime is 81323239169. The next prime is 81323239213. The reversal of 81323239192 is 29193232318.

It is a super-2 number, since 2×81323239192² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 219184 + ... + 459007.

It is an arithmetic number, because the mean of its divisors is an integer number (5136032790).

Almost surely, 2^81323239192 is an apocalyptic number.

It is an amenable number.

81323239192 is an abundant number, since it is smaller than the sum of its proper divisors (83029810088).

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

81323239192 is a wasteful number, since it uses less digits than its factorization.

81323239192 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 679363 (or 679359 counting only the distinct ones).

The product of its digits is 139968, while the sum is 43.

The spelling of 81323239192 in words is "eighty-one billion, three hundred twenty-three million, two hundred thirty-nine thousand, one hundred ninety-two".