721311247 has 2 divisors, whose sum is σ = 721311248. Its totient is φ = 721311246.

The previous prime is 721311233. The next prime is 721311259. The reversal of 721311247 is 742113127.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 721311247 - 2²⁷ = 587093519 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721311277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360655623 + 360655624.

It is an arithmetic number, because the mean of its divisors is an integer number (360655624).

Almost surely, 2^721311247 is an apocalyptic number.

721311247 is a deficient number, since it is larger than the sum of its proper divisors (1).

721311247 is an equidigital number, since it uses as much as digits as its factorization.

721311247 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2352, while the sum is 28.

The square root of 721311247 is about 26857.2382608488. The cubic root of 721311247 is about 896.8247145816.

The spelling of 721311247 in words is "seven hundred twenty-one million, three hundred eleven thousand, two hundred forty-seven".