72309257 has 2 divisors, whose sum is σ = 72309258. Its totient is φ = 72309256.

The previous prime is 72309247. The next prime is 72309271. The reversal of 72309257 is 75290327.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 58920976 + 13388281 = 7676^2 + 3659^2 .

It is a cyclic number.

It is not a de Polignac number, because 72309257 - 2⁴ = 72309241 is a prime.

It is not a weakly prime, because it can be changed into another prime (72309247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36154628 + 36154629.

It is an arithmetic number, because the mean of its divisors is an integer number (36154629).

Almost surely, 2^72309257 is an apocalyptic number.

It is an amenable number.

72309257 is a deficient number, since it is larger than the sum of its proper divisors (1).

72309257 is an equidigital number, since it uses as much as digits as its factorization.

72309257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 26460, while the sum is 35.

The square root of 72309257 is about 8503.4849914609. The cubic root of 72309257 is about 416.6115439257.

The spelling of 72309257 in words is "seventy-two million, three hundred nine thousand, two hundred fifty-seven".