81075186725 has 24 divisors (see below), whose sum is σ = 108319291080. Its totient is φ = 59841745920.

The previous prime is 81075186679. The next prime is 81075186749. The reversal of 81075186725 is 52768157018.

It can be written as a sum of positive squares in 12 ways, for example, as 6330907489 + 74744279236 = 79567^2 + 273394^2 .

It is not a de Polignac number, because 81075186725 - 2⁸ = 81075186469 is a prime.

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, 619217 + ... + 738633.

It is an arithmetic number, because the mean of its divisors is an integer number (4513303795).

Almost surely, 2^81075186725 is an apocalyptic number.

It is an amenable number.

81075186725 is a deficient number, since it is larger than the sum of its proper divisors (27244104355).

81075186725 is a wasteful number, since it uses less digits than its factorization.

81075186725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121529 (or 121524 counting only the distinct ones).

The product of its (nonzero) digits is 940800, while the sum is 50.

The spelling of 81075186725 in words is "eighty-one billion, seventy-five million, one hundred eighty-six thousand, seven hundred twenty-five".