81670375 has 8 divisors (see below), whose sum is σ = 101924784. Its totient is φ = 65336200.

The previous prime is 81670367. The next prime is 81670441. The reversal of 81670375 is 57307618.

It is not a de Polignac number, because 81670375 - 2³ = 81670367 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 326557 + ... + 326806.

It is an arithmetic number, because the mean of its divisors is an integer number (12740598).

Almost surely, 2^81670375 is an apocalyptic number.

81670375 is a deficient number, since it is larger than the sum of its proper divisors (20254409).

81670375 is an equidigital number, since it uses as much as digits as its factorization.

81670375 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 653378 (or 653368 counting only the distinct ones).

The product of its (nonzero) digits is 35280, while the sum is 37.

The square root of 81670375 is about 9037.1663147250. The cubic root of 81670375 is about 433.8652327778.

The spelling of 81670375 in words is "eighty-one million, six hundred seventy thousand, three hundred seventy-five".