28990909 has 2 divisors, whose sum is σ = 28990910. Its totient is φ = 28990908.

The previous prime is 28990891. The next prime is 28990919. The reversal of 28990909 is 90909982.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27092025 + 1898884 = 5205^2 + 1378^2 .

It is a cyclic number.

It is not a de Polignac number, because 28990909 - 2⁵ = 28990877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28990919) 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 as a sum of consecutive naturals, namely, 14495454 + 14495455.

It is an arithmetic number, because the mean of its divisors is an integer number (14495455).

Almost surely, 2^28990909 is an apocalyptic number.

It is an amenable number.

28990909 is a deficient number, since it is larger than the sum of its proper divisors (1).

28990909 is an equidigital number, since it uses as much as digits as its factorization.

28990909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 104976, while the sum is 46.

The square root of 28990909 is about 5384.3206628135. The cubic root of 28990909 is about 307.1995752682.

The spelling of 28990909 in words is "twenty-eight million, nine hundred ninety thousand, nine hundred nine".