81843894 has 24 divisors (see below), whose sum is σ = 193449672. Its totient is φ = 24801120.

The previous prime is 81843871. The next prime is 81843907. The reversal of 81843894 is 49834818.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 206479 + ... + 206874.

It is an arithmetic number, because the mean of its divisors is an integer number (8060403).

Almost surely, 2^81843894 is an apocalyptic number.

81843894 is an abundant number, since it is smaller than the sum of its proper divisors (111605778).

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

81843894 is a wasteful number, since it uses less digits than its factorization.

81843894 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 413372 (or 413369 counting only the distinct ones).

The product of its digits is 221184, while the sum is 45.

The square root of 81843894 is about 9046.7615200137. The cubic root of 81843894 is about 434.1722825392.

The spelling of 81843894 in words is "eighty-one million, eight hundred forty-three thousand, eight hundred ninety-four".