81672375 has 16 divisors (see below), whose sum is σ = 135903456. Its totient is φ = 43558400.

The previous prime is 81672373. The next prime is 81672401. The reversal of 81672375 is 57327618.

It is not a de Polignac number, because 81672375 - 2¹ = 81672373 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81672373) 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, 108522 + ... + 109271.

It is an arithmetic number, because the mean of its divisors is an integer number (8493966).

Almost surely, 2^81672375 is an apocalyptic number.

81672375 is a deficient number, since it is larger than the sum of its proper divisors (54231081).

81672375 is a wasteful number, since it uses less digits than its factorization.

81672375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 217811 (or 217801 counting only the distinct ones).

The product of its digits is 70560, while the sum is 39.

The square root of 81672375 is about 9037.2769682023. The cubic root of 81672375 is about 433.8687743450.

The spelling of 81672375 in words is "eighty-one million, six hundred seventy-two thousand, three hundred seventy-five".