4428721 has 12 divisors (see below), whose sum is σ = 5156676. Its totient is φ = 3787520.

The previous prime is 4428713. The next prime is 4428737. The reversal of 4428721 is 1278244.

It can be written as a sum of positive squares in 2 ways, for example, as 1742400 + 2686321 = 1320^2 + 1639^2 .

It is not a de Polignac number, because 4428721 - 2³ = 4428713 is a prime.

It is a super-2 number, since 2×4428721² = 39227139391682, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 4428721.

It is not an unprimeable number, because it can be changed into a prime (4428701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 981 + ... + 3133.

It is an arithmetic number, because the mean of its divisors is an integer number (429723).

Almost surely, 2^4428721 is an apocalyptic number.

It is an amenable number.

4428721 is a deficient number, since it is larger than the sum of its proper divisors (727955).

4428721 is a wasteful number, since it uses less digits than its factorization.

4428721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2192 (or 2181 counting only the distinct ones).

The product of its digits is 3584, while the sum is 28.

The square root of 4428721 is about 2104.4526604322. The cubic root of 4428721 is about 164.2200224530.

The spelling of 4428721 in words is "four million, four hundred twenty-eight thousand, seven hundred twenty-one".