81072944 has 20 divisors (see below), whose sum is σ = 157240680. Its totient is φ = 40494720.

The previous prime is 81072923. The next prime is 81072961. The reversal of 81072944 is 44927018.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18659 + ... + 22589.

It is an arithmetic number, because the mean of its divisors is an integer number (7862034).

Almost surely, 2^81072944 is an apocalyptic number.

It is an amenable number.

81072944 is a deficient number, since it is larger than the sum of its proper divisors (76167736).

81072944 is a wasteful number, since it uses less digits than its factorization.

81072944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5228 (or 5222 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 81072944 is about 9004.0515325047. The cubic root of 81072944 is about 432.8047129297.

The spelling of 81072944 in words is "eighty-one million, seventy-two thousand, nine hundred forty-four".