721867844 has 12 divisors (see below), whose sum is σ = 1287104364. Its totient is φ = 354123744.

The previous prime is 721867841. The next prime is 721867859. The reversal of 721867844 is 448768127.

It can be written as a sum of positive squares in 2 ways, for example, as 573027844 + 148840000 = 23938^2 + 12200^2 .

It is not an unprimeable number, because it can be changed into a prime (721867841) 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, 1702307 + ... + 1702730.

It is an arithmetic number, because the mean of its divisors is an integer number (107258697).

Almost surely, 2^721867844 is an apocalyptic number.

It is an amenable number.

721867844 is a deficient number, since it is larger than the sum of its proper divisors (565236520).

721867844 is a wasteful number, since it uses less digits than its factorization.

721867844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3405094 (or 3405092 counting only the distinct ones).

The product of its digits is 602112, while the sum is 47.

The square root of 721867844 is about 26867.5984040256. The cubic root of 721867844 is about 897.0553323668.

The spelling of 721867844 in words is "seven hundred twenty-one million, eight hundred sixty-seven thousand, eight hundred forty-four".