721317323 has 2 divisors, whose sum is σ = 721317324. Its totient is φ = 721317322.

The previous prime is 721317239. The next prime is 721317353. The reversal of 721317323 is 323713127.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 721317323 - 2²⁶ = 654208459 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (721317353) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360658661 + 360658662.

It is an arithmetic number, because the mean of its divisors is an integer number (360658662).

Almost surely, 2^721317323 is an apocalyptic number.

721317323 is a deficient number, since it is larger than the sum of its proper divisors (1).

721317323 is an equidigital number, since it uses as much as digits as its factorization.

721317323 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5292, while the sum is 29.

The square root of 721317323 is about 26857.3513772300. The cubic root of 721317323 is about 896.8272327233.

The spelling of 721317323 in words is "seven hundred twenty-one million, three hundred seventeen thousand, three hundred twenty-three".