28090909 has 16 divisors (see below), whose sum is σ = 35392896. Its totient is φ = 21657600.

The previous prime is 28090897. The next prime is 28090963. The reversal of 28090909 is 90909082.

It is a cyclic number.

It is not a de Polignac number, because 28090909 - 2⁵ = 28090877 is a prime.

28090909 is a modest number, since divided by 90909 gives 28 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28090969) 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, 5589 + ... + 9349.

It is an arithmetic number, because the mean of its divisors is an integer number (2212056).

Almost surely, 2^28090909 is an apocalyptic number.

It is an amenable number.

28090909 is a deficient number, since it is larger than the sum of its proper divisors (7301987).

28090909 is a wasteful number, since it uses less digits than its factorization.

28090909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3876.

The product of its (nonzero) digits is 11664, while the sum is 37.

The square root of 28090909 is about 5300.0857540232. The cubic root of 28090909 is about 303.9871770041.

The spelling of 28090909 in words is "twenty-eight million, ninety thousand, nine hundred nine".