81247444 has 24 divisors (see below), whose sum is σ = 147571200. Its totient is φ = 39093600.

The previous prime is 81247433. The next prime is 81247457. The reversal of 81247444 is 44474218.

It is a super-2 number, since 2×81247444² = 13202294313066272, which contains 22 as substring.

It is a congruent 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, 40669 + ... + 42619.

It is an arithmetic number, because the mean of its divisors is an integer number (6148800).

Almost surely, 2^81247444 is an apocalyptic number.

It is an amenable number.

81247444 is a deficient number, since it is larger than the sum of its proper divisors (66323756).

81247444 is a wasteful number, since it uses less digits than its factorization.

81247444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2343 (or 2341 counting only the distinct ones).

The product of its digits is 28672, while the sum is 34.

The square root of 81247444 is about 9013.7364061747. The cubic root of 81247444 is about 433.1150108646.

The spelling of 81247444 in words is "eighty-one million, two hundred forty-seven thousand, four hundred forty-four".