28866609 has 24 divisors (see below), whose sum is σ = 43116840. Its totient is φ = 18600192.

The previous prime is 28866599. The next prime is 28866637. The reversal of 28866609 is 90666882.

It can be written as a sum of positive squares in 4 ways, for example, as 8643600 + 20223009 = 2940^2 + 4497^2 .

It is not a de Polignac number, because 28866609 - 2¹² = 28862513 is a prime.

It is a super-2 number, since 2×28866609² = 1666562230317762, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28866689) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 34407 + ... + 35235.

It is an arithmetic number, because the mean of its divisors is an integer number (1796535).

Almost surely, 2^28866609 is an apocalyptic number.

It is an amenable number.

28866609 is a deficient number, since it is larger than the sum of its proper divisors (14250231).

28866609 is a wasteful number, since it uses less digits than its factorization.

28866609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 961 (or 958 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 45.

The square root of 28866609 is about 5372.7654890196. The cubic root of 28866609 is about 306.7599016816.

The spelling of 28866609 in words is "twenty-eight million, eight hundred sixty-six thousand, six hundred nine".