81291679292 has 24 divisors (see below), whose sum is σ = 143228091552. Its totient is φ = 40369464000.

The previous prime is 81291679291. The next prime is 81291679319. The reversal of 81291679292 is 29297619218.

It is a super-2 number, since 2×81291679292² (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 (81291679291) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5392838 + ... + 5407890.

It is an arithmetic number, because the mean of its divisors is an integer number (5967837148).

Almost surely, 2^81291679292 is an apocalyptic number.

It is an amenable number.

81291679292 is a deficient number, since it is larger than the sum of its proper divisors (61936412260).

81291679292 is a wasteful number, since it uses less digits than its factorization.

81291679292 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24149 (or 24147 counting only the distinct ones).

The product of its digits is 1959552, while the sum is 56.

The spelling of 81291679292 in words is "eighty-one billion, two hundred ninety-one million, six hundred seventy-nine thousand, two hundred ninety-two".