721334217 has 4 divisors (see below), whose sum is σ = 961778960. Its totient is φ = 480889476.

The previous prime is 721334213. The next prime is 721334269. The reversal of 721334217 is 712433127.

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 not a de Polignac number, because 721334217 - 2² = 721334213 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721334213) 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, 120222367 + ... + 120222372.

It is an arithmetic number, because the mean of its divisors is an integer number (240444740).

Almost surely, 2^721334217 is an apocalyptic number.

It is an amenable number.

721334217 is a deficient number, since it is larger than the sum of its proper divisors (240444743).

721334217 is a wasteful number, since it uses less digits than its factorization.

721334217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 240444742.

The product of its digits is 7056, while the sum is 30.

The square root of 721334217 is about 26857.6658889040. The cubic root of 721334217 is about 896.8342342100.

The spelling of 721334217 in words is "seven hundred twenty-one million, three hundred thirty-four thousand, two hundred seventeen".