81392170 has 16 divisors (see below), whose sum is σ = 152876160. Its totient is φ = 31141264.

The previous prime is 81392161. The next prime is 81392221. The reversal of 81392170 is 7129318.

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, 176710 + ... + 177169.

It is an arithmetic number, because the mean of its divisors is an integer number (9554760).

Almost surely, 2^81392170 is an apocalyptic number.

81392170 is a deficient number, since it is larger than the sum of its proper divisors (71483990).

81392170 is a wasteful number, since it uses less digits than its factorization.

81392170 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 353909.

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 81392170 is about 9021.7609145887. The cubic root of 81392170 is about 433.3720274455.

The spelling of 81392170 in words is "eighty-one million, three hundred ninety-two thousand, one hundred seventy".