81894534 has 16 divisors (see below), whose sum is σ = 165293040. Its totient is φ = 27047520.

The previous prime is 81894511. The next prime is 81894551. The reversal of 81894534 is 43549818.

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, 61957 + ... + 63264.

It is an arithmetic number, because the mean of its divisors is an integer number (10330815).

Almost surely, 2^81894534 is an apocalyptic number.

81894534 is an abundant number, since it is smaller than the sum of its proper divisors (83398506).

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

81894534 is a wasteful number, since it uses less digits than its factorization.

81894534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125335.

The product of its digits is 138240, while the sum is 42.

The square root of 81894534 is about 9049.5598788007. The cubic root of 81894534 is about 434.2618105021.

It can be divided in two parts, 81894 and 534, that added together give a palindrome (82428).

The spelling of 81894534 in words is "eighty-one million, eight hundred ninety-four thousand, five hundred thirty-four".