81672325 has 24 divisors (see below), whose sum is σ = 116296128. Its totient is φ = 55735680.

The previous prime is 81672319. The next prime is 81672359. The reversal of 81672325 is 52327618.

It is a happy number.

It is not a de Polignac number, because 81672325 - 2⁵ = 81672293 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 39774 + ... + 41776.

It is an arithmetic number, because the mean of its divisors is an integer number (4845672).

Almost surely, 2^81672325 is an apocalyptic number.

It is an amenable number.

81672325 is a deficient number, since it is larger than the sum of its proper divisors (34623803).

81672325 is a wasteful number, since it uses less digits than its factorization.

81672325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2253 (or 2248 counting only the distinct ones).

The product of its digits is 20160, while the sum is 34.

The square root of 81672325 is about 9037.2742018819. The cubic root of 81672325 is about 433.8686858065.

The spelling of 81672325 in words is "eighty-one million, six hundred seventy-two thousand, three hundred twenty-five".