72400709 has 2 divisors, whose sum is σ = 72400710. Its totient is φ = 72400708.

The previous prime is 72400693. The next prime is 72400721. The reversal of 72400709 is 90700427.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39967684 + 32433025 = 6322^2 + 5695^2 .

It is a cyclic number.

It is not a de Polignac number, because 72400709 - 2⁴ = 72400693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72400799) 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 as a sum of consecutive naturals, namely, 36200354 + 36200355.

It is an arithmetic number, because the mean of its divisors is an integer number (36200355).

Almost surely, 2^72400709 is an apocalyptic number.

It is an amenable number.

72400709 is a deficient number, since it is larger than the sum of its proper divisors (1).

72400709 is an equidigital number, since it uses as much as digits as its factorization.

72400709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3528, while the sum is 29.

The square root of 72400709 is about 8508.8606170274. The cubic root of 72400709 is about 416.7871042419.

The spelling of 72400709 in words is "seventy-two million, four hundred thousand, seven hundred nine".