72750509 has 4 divisors (see below), whose sum is σ = 78346716. Its totient is φ = 67154304.

The previous prime is 72750499. The next prime is 72750511. The reversal of 72750509 is 90505727.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90505727 = 13 ⋅6961979.

It can be written as a sum of positive squares in 2 ways, for example, as 8702500 + 64048009 = 2950^2 + 8003^2 .

It is a cyclic number.

It is not a de Polignac number, because 72750509 - 2⁴ = 72750493 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 (72750569) 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 3 ways as a sum of consecutive naturals, for example, 2798084 + ... + 2798109.

It is an arithmetic number, because the mean of its divisors is an integer number (19586679).

Almost surely, 2^72750509 is an apocalyptic number.

It is an amenable number.

72750509 is a deficient number, since it is larger than the sum of its proper divisors (5596207).

72750509 is a wasteful number, since it uses less digits than its factorization.

72750509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5596206.

The product of its (nonzero) digits is 22050, while the sum is 35.

The square root of 72750509 is about 8529.3908926722. The cubic root of 72750509 is about 417.4572540409.

The spelling of 72750509 in words is "seventy-two million, seven hundred fifty thousand, five hundred nine".