81312438294 has 48 divisors (see below), whose sum is σ = 178879691328. Its totient is φ = 26688671856.

The previous prime is 81312438289. The next prime is 81312438349. The reversal of 81312438294 is 49283421318.

81312438294 is a `hidden beast` number, since 8 + 1 + 312 + 43 + 8 + 294 = 666.

It is a super-2 number, since 2×81312438294² (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 23 ways as a sum of consecutive naturals, for example, 3252189 + ... + 3277095.

It is an arithmetic number, because the mean of its divisors is an integer number (3726660236).

Almost surely, 2^81312438294 is an apocalyptic number.

81312438294 is an abundant number, since it is smaller than the sum of its proper divisors (97567253034).

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

81312438294 is a wasteful number, since it uses less digits than its factorization.

81312438294 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27689 (or 27686 counting only the distinct ones).

The product of its digits is 331776, while the sum is 45.

The spelling of 81312438294 in words is "eighty-one billion, three hundred twelve million, four hundred thirty-eight thousand, two hundred ninety-four".