81275145231 has 32 divisors (see below), whose sum is σ = 125331148800. Its totient is φ = 45887466240.

The previous prime is 81275145227. The next prime is 81275145247. The reversal of 81275145231 is 13254157218.

It is not a de Polignac number, because 81275145231 - 2² = 81275145227 is a prime.

It is a super-2 number, since 2×81275145231² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81275145231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81275145221) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2655586 + ... + 2686016.

It is an arithmetic number, because the mean of its divisors is an integer number (3916598400).

Almost surely, 2^81275145231 is an apocalyptic number.

81275145231 is a deficient number, since it is larger than the sum of its proper divisors (44056003569).

81275145231 is a wasteful number, since it uses less digits than its factorization.

81275145231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31959.

The product of its digits is 67200, while the sum is 39.

The spelling of 81275145231 in words is "eighty-one billion, two hundred seventy-five million, one hundred forty-five thousand, two hundred thirty-one".