721421713 has 4 divisors (see below), whose sum is σ = 728164080. Its totient is φ = 714679348.

The previous prime is 721421681. The next prime is 721421737. The reversal of 721421713 is 317124127.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 721421713 - 2⁵ = 721421681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721424713) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3371023 + ... + 3371236.

It is an arithmetic number, because the mean of its divisors is an integer number (182041020).

Almost surely, 2^721421713 is an apocalyptic number.

It is an amenable number.

721421713 is a deficient number, since it is larger than the sum of its proper divisors (6742367).

721421713 is a wasteful number, since it uses less digits than its factorization.

721421713 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6742366.

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

The square root of 721421713 is about 26859.2947226840. The cubic root of 721421713 is about 896.8704939787.

The spelling of 721421713 in words is "seven hundred twenty-one million, four hundred twenty-one thousand, seven hundred thirteen".