81966244 has 6 divisors (see below), whose sum is σ = 143440934. Its totient is φ = 40983120.

The previous prime is 81966233. The next prime is 81966251. The reversal of 81966244 is 44266918.

It can be written as a sum of positive squares in only one way, i.e., 72590400 + 9375844 = 8520^2 + 3062^2 .

It is a junction number, because it is equal to n+sod(n) for n = 81966197 and 81966206.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10245777 + ... + 10245784.

Almost surely, 2^81966244 is an apocalyptic number.

It is an amenable number.

81966244 is a deficient number, since it is larger than the sum of its proper divisors (61474690).

81966244 is a wasteful number, since it uses less digits than its factorization.

81966244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20491565 (or 20491563 counting only the distinct ones).

The product of its digits is 82944, while the sum is 40.

The square root of 81966244 is about 9053.5210829820. The cubic root of 81966244 is about 434.3885256317.

The spelling of 81966244 in words is "eighty-one million, nine hundred sixty-six thousand, two hundred forty-four".