28276009 has 4 divisors (see below), whose sum is σ = 29764240. Its totient is φ = 26787780.

The previous prime is 28276007. The next prime is 28276013. The reversal of 28276009 is 90067282.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 90067282 = 2 ⋅45033641.

It is a cyclic number.

It is not a de Polignac number, because 28276009 - 2¹ = 28276007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28276007) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 744087 + ... + 744124.

It is an arithmetic number, because the mean of its divisors is an integer number (7441060).

Almost surely, 2^28276009 is an apocalyptic number.

It is an amenable number.

28276009 is a deficient number, since it is larger than the sum of its proper divisors (1488231).

28276009 is a wasteful number, since it uses less digits than its factorization.

28276009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1488230.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 28276009 is about 5317.5190643758. The cubic root of 28276009 is about 304.6534054455.

It can be divided in two parts, 2827 and 6009, that added together give a square (8836 = 94²).

The spelling of 28276009 in words is "twenty-eight million, two hundred seventy-six thousand, nine".