81370194 has 16 divisors (see below), whose sum is σ = 172313568. Its totient is φ = 25527872.

The previous prime is 81370169. The next prime is 81370213. The reversal of 81370194 is 49107318.

It is a super-2 number, since 2×81370194² = 13242216943195272, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 398772 + ... + 398975.

It is an arithmetic number, because the mean of its divisors is an integer number (10769598).

Almost surely, 2^81370194 is an apocalyptic number.

81370194 is an abundant number, since it is smaller than the sum of its proper divisors (90943374).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81370194 is a wasteful number, since it uses less digits than its factorization.

81370194 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 797769.

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 81370194 is about 9020.5428883189. The cubic root of 81370194 is about 433.3330202496. Note that the first 3 decimals are identical.

Subtracting from 81370194 its product of nonzero digits (6048), we obtain a triangular number (81364146 = T₁₂₇₅₆).

The spelling of 81370194 in words is "eighty-one million, three hundred seventy thousand, one hundred ninety-four".