81679085 has 8 divisors (see below), whose sum is σ = 98073720. Its totient is φ = 65304064.

The previous prime is 81679063. The next prime is 81679111. The reversal of 81679085 is 58097618.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 5396329 + 76282756 = 2323^2 + 8734^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 81679085 - 2⁶ = 81679021 is a prime.

It is a Curzon 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, 6809 + ... + 14481.

It is an arithmetic number, because the mean of its divisors is an integer number (12259215).

Almost surely, 2^81679085 is an apocalyptic number.

It is an amenable number.

81679085 is a deficient number, since it is larger than the sum of its proper divisors (16394635).

81679085 is a wasteful number, since it uses less digits than its factorization.

81679085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9807.

The product of its (nonzero) digits is 120960, while the sum is 44.

The square root of 81679085 is about 9037.6482007212. The cubic root of 81679085 is about 433.8806558809.

The spelling of 81679085 in words is "eighty-one million, six hundred seventy-nine thousand, eighty-five".