721343213 has 4 divisors (see below), whose sum is σ = 722336160. Its totient is φ = 720350268.

The previous prime is 721343191. The next prime is 721343237. The reversal of 721343213 is 312343127.

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 721343213 - 2¹⁰ = 721342189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721345213) 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, 495383 + ... + 496836.

It is an arithmetic number, because the mean of its divisors is an integer number (180584040).

Almost surely, 2^721343213 is an apocalyptic number.

It is an amenable number.

721343213 is a deficient number, since it is larger than the sum of its proper divisors (992947).

721343213 is an equidigital number, since it uses as much as digits as its factorization.

721343213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 992946.

The product of its digits is 3024, while the sum is 26.

The square root of 721343213 is about 26857.8333638438. The cubic root of 721343213 is about 896.8379624343.

The spelling of 721343213 in words is "seven hundred twenty-one million, three hundred forty-three thousand, two hundred thirteen".