81172355325 has 48 divisors (see below), whose sum is σ = 138583130112. Its totient is φ = 41880600000.

The previous prime is 81172355321. The next prime is 81172355339. The reversal of 81172355325 is 52355327118.

It is not a de Polignac number, because 81172355325 - 2² = 81172355321 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81172355321) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 10205100 + ... + 10213050.

It is an arithmetic number, because the mean of its divisors is an integer number (2887148544).

Almost surely, 2^81172355325 is an apocalyptic number.

It is an amenable number.

81172355325 is a deficient number, since it is larger than the sum of its proper divisors (57410774787).

81172355325 is a wasteful number, since it uses less digits than its factorization.

81172355325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12386 (or 12381 counting only the distinct ones).

The product of its digits is 252000, while the sum is 42.

The spelling of 81172355325 in words is "eighty-one billion, one hundred seventy-two million, three hundred fifty-five thousand, three hundred twenty-five".