81597244 has 12 divisors (see below), whose sum is σ = 142884000. Its totient is φ = 40773248.

The previous prime is 81597233. The next prime is 81597251. The reversal of 81597244 is 44279518.

It is a super-2 number, since 2×81597244² = 13316220456791072, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81597197 and 81597206.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2157 + ... + 12955.

It is an arithmetic number, because the mean of its divisors is an integer number (11907000).

Almost surely, 2^81597244 is an apocalyptic number.

It is an amenable number.

81597244 is a deficient number, since it is larger than the sum of its proper divisors (61286756).

81597244 is a wasteful number, since it uses less digits than its factorization.

81597244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12692 (or 12690 counting only the distinct ones).

The product of its digits is 80640, while the sum is 40.

The square root of 81597244 is about 9033.1192840569. The cubic root of 81597244 is about 433.7356938699.

The spelling of 81597244 in words is "eighty-one million, five hundred ninety-seven thousand, two hundred forty-four".