81237144 has 32 divisors (see below), whose sum is σ = 204225840. Its totient is φ = 26928000.

The previous prime is 81237139. The next prime is 81237151. The reversal of 81237144 is 44173218.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 5007 + ... + 13694.

Almost surely, 2^81237144 is an apocalyptic number.

It is an amenable number.

81237144 is an abundant number, since it is smaller than the sum of its proper divisors (122988696).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81237144 is a wasteful number, since it uses less digits than its factorization.

81237144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18891 (or 18887 counting only the distinct ones).

The product of its digits is 5376, while the sum is 30.

The square root of 81237144 is about 9013.1650378765. The cubic root of 81237144 is about 433.0967076297.

The spelling of 81237144 in words is "eighty-one million, two hundred thirty-seven thousand, one hundred forty-four".