81670 has 8 divisors (see below), whose sum is σ = 147024. Its totient is φ = 32664.

The previous prime is 81667. The next prime is 81671. The reversal of 81670 is 7618.

It is a sphenic number, since it is the product of 3 distinct primes.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81671) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4074 + ... + 4093.

It is an arithmetic number, because the mean of its divisors is an integer number (18378).

2⁸¹⁶⁷⁰ is an apocalyptic number.

81670 is a deficient number, since it is larger than the sum of its proper divisors (65354).

81670 is a wasteful number, since it uses less digits than its factorization.

81670 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8174.

The product of its (nonzero) digits is 336, while the sum is 22.

The square root of 81670 is about 285.7796353836. The cubic root of 81670 is about 43.3864568727.

The spelling of 81670 in words is "eighty-one thousand, six hundred seventy".