721675447 has 2 divisors, whose sum is σ = 721675448. Its totient is φ = 721675446.

The previous prime is 721675421. The next prime is 721675477. The reversal of 721675447 is 744576127.

It is a weak prime.

It is an emirp because it is prime and its reverse (744576127) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 721675447 - 2²³ = 713286839 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721675477) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360837723 + 360837724.

It is an arithmetic number, because the mean of its divisors is an integer number (360837724).

Almost surely, 2^721675447 is an apocalyptic number.

721675447 is a deficient number, since it is larger than the sum of its proper divisors (1).

721675447 is an equidigital number, since it uses as much as digits as its factorization.

721675447 is an evil number, because the sum of its binary digits is even.

The product of its digits is 329280, while the sum is 43.

The square root of 721675447 is about 26864.0177002622. The cubic root of 721675447 is about 896.9756289087.

The spelling of 721675447 in words is "seven hundred twenty-one million, six hundred seventy-five thousand, four hundred forty-seven".