28990009 has 2 divisors, whose sum is σ = 28990010. Its totient is φ = 28990008.

The previous prime is 28990001. The next prime is 28990019. The reversal of 28990009 is 90009982.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15776784 + 13213225 = 3972^2 + 3635^2 .

It is a cyclic number.

It is not a de Polignac number, because 28990009 - 2³ = 28990001 is a prime.

It is a Chen prime.

It is equal to p_1799092 and since 28990009 and 1799092 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28990009.

It is not a weakly prime, because it can be changed into another prime (28990001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14495004 + 14495005.

It is an arithmetic number, because the mean of its divisors is an integer number (14495005).

Almost surely, 2^28990009 is an apocalyptic number.

It is an amenable number.

28990009 is a deficient number, since it is larger than the sum of its proper divisors (1).

28990009 is an equidigital number, since it uses as much as digits as its factorization.

28990009 is an evil number, because the sum of its binary digits is even.

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

The square root of 28990009 is about 5384.2370861618. The cubic root of 28990009 is about 307.1963963121.

The spelling of 28990009 in words is "twenty-eight million, nine hundred ninety thousand, nine".