81444418 has 16 divisors (see below), whose sum is σ = 134962560. Its totient is φ = 36550800.

The previous prime is 81444413. The next prime is 81444439.

81444418 is nontrivially palindromic in base 10.

It is not an unprimeable number, because it can be changed into a prime (81444413) 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, 21693 + ... + 25168.

It is an arithmetic number, because the mean of its divisors is an integer number (8435160).

Almost surely, 2^81444418 is an apocalyptic number.

81444418 is a deficient number, since it is larger than the sum of its proper divisors (53518142).

81444418 is a wasteful number, since it uses less digits than its factorization.

81444418 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46953.

The product of its digits is 16384, while the sum is 34.

The square root of 81444418 is about 9024.6561153320. The cubic root of 81444418 is about 433.4647389777.

The spelling of 81444418 in words is "eighty-one million, four hundred forty-four thousand, four hundred eighteen".