28199809 has 16 divisors (see below), whose sum is σ = 31847040. Its totient is φ = 24744960.

The previous prime is 28199807. The next prime is 28199833. The reversal of 28199809 is 90899182.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 28199809 - 2¹ = 28199807 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28199807) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 78372 + ... + 78730.

It is an arithmetic number, because the mean of its divisors is an integer number (1990440).

Almost surely, 2^28199809 is an apocalyptic number.

It is an amenable number.

28199809 is a deficient number, since it is larger than the sum of its proper divisors (3647231).

28199809 is a wasteful number, since it uses less digits than its factorization.

28199809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 600.

The product of its (nonzero) digits is 93312, while the sum is 46.

The square root of 28199809 is about 5310.3492352198. The cubic root of 28199809 is about 304.3794927426.

The spelling of 28199809 in words is "twenty-eight million, one hundred ninety-nine thousand, eight hundred nine".