2217728 has 18 divisors (see below), whose sum is σ = 4427304. Its totient is φ = 1108736.

The previous prime is 2217673. The next prime is 2217749. The reversal of 2217728 is 8277122.

It is a self number, because there is not a number n which added to its sum of digits gives 2217728.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4076 + ... + 4587.

2^2217728 is an apocalyptic number.

It is an amenable number.

2217728 is a deficient number, since it is larger than the sum of its proper divisors (2209576).

2217728 is an frugal number, since it uses more digits than its factorization.

2217728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8679 (or 8665 counting only the distinct ones).

The product of its digits is 3136, while the sum is 29.

The square root of 2217728 is about 1489.2038141235. The cubic root of 2217728 is about 130.4075572420.

The spelling of 2217728 in words is "two million, two hundred seventeen thousand, seven hundred twenty-eight".