81960131831 has 8 divisors (see below), whose sum is σ = 86280732720. Its totient is φ = 77640221952.

The previous prime is 81960131809. The next prime is 81960131849. The reversal of 81960131831 is 13813106918.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81960131831 - 2²² = 81955937527 is a prime.

It is a super-2 number, since 2×81960131831² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81960131131) 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, 80231 + ... + 412743.

It is an arithmetic number, because the mean of its divisors is an integer number (10785091590).

Almost surely, 2^81960131831 is an apocalyptic number.

81960131831 is a deficient number, since it is larger than the sum of its proper divisors (4320600889).

81960131831 is a wasteful number, since it uses less digits than its factorization.

81960131831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 345505.

The product of its (nonzero) digits is 31104, while the sum is 41.

The spelling of 81960131831 in words is "eighty-one billion, nine hundred sixty million, one hundred thirty-one thousand, eight hundred thirty-one".