721222345 has 4 divisors (see below), whose sum is σ = 865466820. Its totient is φ = 576977872.

The previous prime is 721222309. The next prime is 721222391. The reversal of 721222345 is 543222127.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 128981449 + 592240896 = 11357^2 + 24336^2 .

It is a cyclic number.

It is not a de Polignac number, because 721222345 - 2⁷ = 721222217 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72122230 + ... + 72122239.

It is an arithmetic number, because the mean of its divisors is an integer number (216366705).

Almost surely, 2^721222345 is an apocalyptic number.

It is an amenable number.

721222345 is a deficient number, since it is larger than the sum of its proper divisors (144244475).

721222345 is a wasteful number, since it uses less digits than its factorization.

721222345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144244474.

The product of its digits is 6720, while the sum is 28.

The square root of 721222345 is about 26855.5831253019. The cubic root of 721222345 is about 896.7878683580.

The spelling of 721222345 in words is "seven hundred twenty-one million, two hundred twenty-two thousand, three hundred forty-five".