81475244 has 6 divisors (see below), whose sum is σ = 142581684. Its totient is φ = 40737620.

The previous prime is 81475243. The next prime is 81475259. The reversal of 81475244 is 44257418.

It is not an unprimeable number, because it can be changed into a prime (81475243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10184402 + ... + 10184409.

It is an arithmetic number, because the mean of its divisors is an integer number (23763614).

Almost surely, 2^81475244 is an apocalyptic number.

It is an amenable number.

81475244 is a deficient number, since it is larger than the sum of its proper divisors (61106440).

81475244 is a wasteful number, since it uses less digits than its factorization.

81475244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20368815 (or 20368813 counting only the distinct ones).

The product of its digits is 35840, while the sum is 35.

The square root of 81475244 is about 9026.3638304691. The cubic root of 81475244 is about 433.5194196173.

The spelling of 81475244 in words is "eighty-one million, four hundred seventy-five thousand, two hundred forty-four".