28737009 has 24 divisors (see below), whose sum is σ = 47611200. Its totient is φ = 16361568.

The previous prime is 28736989. The next prime is 28737061. The reversal of 28737009 is 90073782.

28737009 is a `hidden beast` number, since 287 + 370 + 0 + 9 = 666.

It is not a de Polignac number, because 28737009 - 2⁵ = 28736977 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28737109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21334 + ... + 22640.

It is an arithmetic number, because the mean of its divisors is an integer number (1983800).

Almost surely, 2^28737009 is an apocalyptic number.

It is an amenable number.

28737009 is a deficient number, since it is larger than the sum of its proper divisors (18874191).

28737009 is a wasteful number, since it uses less digits than its factorization.

28737009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1669 (or 1666 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 36.

The square root of 28737009 is about 5360.6910935065. The cubic root of 28737009 is about 306.3001348437.

The spelling of 28737009 in words is "twenty-eight million, seven hundred thirty-seven thousand, nine".