28338661 has 4 divisors (see below), whose sum is σ = 30518572. Its totient is φ = 26158752.

The previous prime is 28338659. The next prime is 28338683. The reversal of 28338661 is 16683382.

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 1454436 + 26884225 = 1206^2 + 5185^2 .

It is a cyclic number.

It is not a de Polignac number, because 28338661 - 2¹ = 28338659 is a prime.

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 28338661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28338641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1089936 + ... + 1089961.

It is an arithmetic number, because the mean of its divisors is an integer number (7629643).

Almost surely, 2^28338661 is an apocalyptic number.

It is an amenable number.

28338661 is a deficient number, since it is larger than the sum of its proper divisors (2179911).

28338661 is a wasteful number, since it uses less digits than its factorization.

28338661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2179910.

The product of its digits is 41472, while the sum is 37.

The square root of 28338661 is about 5323.4068978428. The cubic root of 28338661 is about 304.8782493543.

The spelling of 28338661 in words is "twenty-eight million, three hundred thirty-eight thousand, six hundred sixty-one".