72530309 has 2 divisors, whose sum is σ = 72530310. Its totient is φ = 72530308.

The previous prime is 72530261. The next prime is 72530317. The reversal of 72530309 is 90303527.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 70930084 + 1600225 = 8422^2 + 1265^2 .

It is a cyclic number.

It is not a de Polignac number, because 72530309 - 2⁸ = 72530053 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72530329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36265154 + 36265155.

It is an arithmetic number, because the mean of its divisors is an integer number (36265155).

Almost surely, 2^72530309 is an apocalyptic number.

It is an amenable number.

72530309 is a deficient number, since it is larger than the sum of its proper divisors (1).

72530309 is an equidigital number, since it uses as much as digits as its factorization.

72530309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5670, while the sum is 29.

The square root of 72530309 is about 8516.4728027511. The cubic root of 72530309 is about 417.0356442147.

The spelling of 72530309 in words is "seventy-two million, five hundred thirty thousand, three hundred nine".