81894441 has 8 divisors (see below), whose sum is σ = 109296000. Its totient is φ = 54544592.

The previous prime is 81894413. The next prime is 81894443. The reversal of 81894441 is 14449818.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81894441 - 2¹³ = 81886249 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81894441.

It is not an unprimeable number, because it can be changed into a prime (81894443) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9066 + ... + 15683.

It is an arithmetic number, because the mean of its divisors is an integer number (13662000).

Almost surely, 2^81894441 is an apocalyptic number.

It is an amenable number.

81894441 is a deficient number, since it is larger than the sum of its proper divisors (27401559).

81894441 is a wasteful number, since it uses less digits than its factorization.

81894441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25855.

The product of its digits is 36864, while the sum is 39.

The square root of 81894441 is about 9049.5547404278. The cubic root of 81894441 is about 434.2616461185.

It can be divided in two parts, 818 and 94441, that added together give a palindrome (95259).

The spelling of 81894441 in words is "eighty-one million, eight hundred ninety-four thousand, four hundred forty-one".