81145444 has 12 divisors (see below), whose sum is σ = 142377984. Its totient is φ = 40466024.

The previous prime is 81145417. The next prime is 81145457. The reversal of 81145444 is 44454118.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24952 + ... + 28015.

It is an arithmetic number, because the mean of its divisors is an integer number (11864832).

Almost surely, 2^81145444 is an apocalyptic number.

It is an amenable number.

81145444 is a deficient number, since it is larger than the sum of its proper divisors (61232540).

81145444 is a wasteful number, since it uses less digits than its factorization.

81145444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53354 (or 53352 counting only the distinct ones).

The product of its digits is 10240, while the sum is 31.

The square root of 81145444 is about 9008.0765982534. The cubic root of 81145444 is about 432.9336872885.

The spelling of 81145444 in words is "eighty-one million, one hundred forty-five thousand, four hundred forty-four".