81223734231 has 20 divisors (see below), whose sum is σ = 121344142392. Its totient is φ = 54144728208.

The previous prime is 81223734227. The next prime is 81223734269. The reversal of 81223734231 is 13243732218.

81223734231 is a `hidden beast` number, since 8 + 1 + 223 + 7 + 3 + 423 + 1 = 666.

It is not a de Polignac number, because 81223734231 - 2² = 81223734227 is a prime.

It is a super-2 number, since 2×81223734231² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81223734281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1177996 + ... + 1245038.

Almost surely, 2^81223734231 is an apocalyptic number.

81223734231 is a gapful number since it is divisible by the number (81) formed by its first and last digit.

81223734231 is a deficient number, since it is larger than the sum of its proper divisors (40120408161).

81223734231 is a wasteful number, since it uses less digits than its factorization.

81223734231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82012 (or 82003 counting only the distinct ones).

The product of its digits is 48384, while the sum is 36.

The spelling of 81223734231 in words is "eighty-one billion, two hundred twenty-three million, seven hundred thirty-four thousand, two hundred thirty-one".