81894918 has 32 divisors (see below), whose sum is σ = 188176896. Its totient is φ = 23275008.

The previous prime is 81894893. The next prime is 81894937. The reversal of 81894918 is 81949818.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3055 + ... + 13157.

It is an arithmetic number, because the mean of its divisors is an integer number (5880528).

Almost surely, 2^81894918 is an apocalyptic number.

81894918 is an abundant number, since it is smaller than the sum of its proper divisors (106281978).

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

81894918 is a wasteful number, since it uses less digits than its factorization.

81894918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10308.

The product of its digits is 165888, while the sum is 48.

The square root of 81894918 is about 9049.5810952773. The cubic root of 81894918 is about 434.2624892461.

The spelling of 81894918 in words is "eighty-one million, eight hundred ninety-four thousand, nine hundred eighteen".