81320125 has 16 divisors (see below), whose sum is σ = 101746944. Its totient is φ = 64890000.

The previous prime is 81320123. The next prime is 81320131. The reversal of 81320125 is 52102318.

It is not a de Polignac number, because 81320125 - 2¹ = 81320123 is a prime.

It is a super-2 number, since 2×81320125² = 13225925460031250, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81320096 and 81320105.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81320123) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 78360 + ... + 79390.

It is an arithmetic number, because the mean of its divisors is an integer number (6359184).

Almost surely, 2^81320125 is an apocalyptic number.

It is an amenable number.

81320125 is a deficient number, since it is larger than the sum of its proper divisors (20426819).

81320125 is a wasteful number, since it uses less digits than its factorization.

81320125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1677 (or 1667 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 81320125 is about 9017.7671848413. The cubic root of 81320125 is about 433.2441220033.

The spelling of 81320125 in words is "eighty-one million, three hundred twenty thousand, one hundred twenty-five".