844500721 has 16 divisors (see below), whose sum is σ = 906477264. Its totient is φ = 783949824.

The previous prime is 844500697. The next prime is 844500773. The reversal of 844500721 is 127005448.

844500721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 181953121 + 662547600 = 13489^2 + 25740^2 .

It is a cyclic number.

It is not a de Polignac number, because 844500721 - 2⁷ = 844500593 is a prime.

It is not an unprimeable number, because it can be changed into a prime (844500121) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 614391 + ... + 615763.

It is an arithmetic number, because the mean of its divisors is an integer number (56654829).

Almost surely, 2^844500721 is an apocalyptic number.

It is an amenable number.

844500721 is a deficient number, since it is larger than the sum of its proper divisors (61976543).

844500721 is a wasteful number, since it uses less digits than its factorization.

844500721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1860.

The product of its (nonzero) digits is 8960, while the sum is 31.

The square root of 844500721 is about 29060.2945786859. The cubic root of 844500721 is about 945.2209559569.

The spelling of 844500721 in words is "eight hundred forty-four million, five hundred thousand, seven hundred twenty-one".