73128791 has 4 divisors (see below), whose sum is σ = 73308000. Its totient is φ = 72949584.

The previous prime is 73128779. The next prime is 73128833. The reversal of 73128791 is 19782137.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19782137 = 83 ⋅238339.

It is a cyclic number.

It is not a de Polignac number, because 73128791 - 2¹⁰ = 73127767 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (73128191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 88991 + ... + 89808.

It is an arithmetic number, because the mean of its divisors is an integer number (18327000).

Almost surely, 2^73128791 is an apocalyptic number.

73128791 is a deficient number, since it is larger than the sum of its proper divisors (179209).

73128791 is a wasteful number, since it uses less digits than its factorization.

73128791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179208.

The product of its digits is 21168, while the sum is 38.

The square root of 73128791 is about 8551.5373471675. The cubic root of 73128791 is about 418.1795566427.

The spelling of 73128791 in words is "seventy-three million, one hundred twenty-eight thousand, seven hundred ninety-one".