72591509 has 2 divisors, whose sum is σ = 72591510. Its totient is φ = 72591508.

The previous prime is 72591487. The next prime is 72591511. The reversal of 72591509 is 90519527.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 44182609 + 28408900 = 6647^2 + 5330^2 .

It is a cyclic number.

It is not a de Polignac number, because 72591509 - 2²⁴ = 55814293 is a prime.

Together with 72591511, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72591559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36295754 + 36295755.

It is an arithmetic number, because the mean of its divisors is an integer number (36295755).

Almost surely, 2^72591509 is an apocalyptic number.

It is an amenable number.

72591509 is a deficient number, since it is larger than the sum of its proper divisors (1).

72591509 is an equidigital number, since it uses as much as digits as its factorization.

72591509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28350, while the sum is 38.

The square root of 72591509 is about 8520.0650819111. The cubic root of 72591509 is about 417.1529074049.

The spelling of 72591509 in words is "seventy-two million, five hundred ninety-one thousand, five hundred nine".