73121728 has 28 divisors (see below), whose sum is σ = 152740360. Its totient is φ = 34636032.

The previous prime is 73121683. The next prime is 73121749. The reversal of 73121728 is 82712137.

It is a self number, because there is not a number n which added to its sum of digits gives 73121728.

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, 28851 + ... + 31282.

Almost surely, 2^73121728 is an apocalyptic number.

It is an amenable number.

73121728 is an abundant number, since it is smaller than the sum of its proper divisors (79618632).

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

73121728 is a wasteful number, since it uses less digits than its factorization.

73121728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60164 (or 60154 counting only the distinct ones).

The product of its digits is 4704, while the sum is 31.

The square root of 73121728 is about 8551.1243705141. The cubic root of 73121728 is about 418.1660931934.

It can be divided in two parts, 73 and 121728, that added together give a square (121801 = 349²).

The spelling of 73121728 in words is "seventy-three million, one hundred twenty-one thousand, seven hundred twenty-eight".