81944018 has 16 divisors (see below), whose sum is σ = 132935040. Its totient is φ = 37659216.

The previous prime is 81943993. The next prime is 81944039. The reversal of 81944018 is 81044918.

It is a Curzon 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, 380 + ... + 12807.

It is an arithmetic number, because the mean of its divisors is an integer number (8308440).

Almost surely, 2^81944018 is an apocalyptic number.

81944018 is a deficient number, since it is larger than the sum of its proper divisors (50991022).

81944018 is a wasteful number, since it uses less digits than its factorization.

81944018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13441.

The product of its (nonzero) digits is 9216, while the sum is 35.

The square root of 81944018 is about 9052.2935215336. The cubic root of 81944018 is about 434.3492590926.

The spelling of 81944018 in words is "eighty-one million, nine hundred forty-four thousand, eighteen".