72981844 has 24 divisors (see below), whose sum is σ = 137789960. Its totient is φ = 33623424.

The previous prime is 72981791. The next prime is 72981847. The reversal of 72981844 is 44818927.

It can be written as a sum of positive squares in 4 ways, for example, as 2220100 + 70761744 = 1490^2 + 8412^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 72981844.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72981847) by changing a digit.

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, 42262 + ... + 43954.

Almost surely, 2^72981844 is an apocalyptic number.

It is an amenable number.

72981844 is a deficient number, since it is larger than the sum of its proper divisors (64808116).

72981844 is a wasteful number, since it uses less digits than its factorization.

72981844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2539 (or 2537 counting only the distinct ones).

The product of its digits is 129024, while the sum is 43.

The square root of 72981844 is about 8542.9411797109. The cubic root of 72981844 is about 417.8992683258.

The spelling of 72981844 in words is "seventy-two million, nine hundred eighty-one thousand, eight hundred forty-four".