28736909 has 2 divisors, whose sum is σ = 28736910. Its totient is φ = 28736908.

The previous prime is 28736899. The next prime is 28736921. The reversal of 28736909 is 90963782.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25532809 + 3204100 = 5053^2 + 1790^2 .

It is a cyclic number.

It is not a de Polignac number, because 28736909 - 2¹² = 28732813 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28736909.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28736989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14368454 + 14368455.

It is an arithmetic number, because the mean of its divisors is an integer number (14368455).

Almost surely, 2^28736909 is an apocalyptic number.

It is an amenable number.

28736909 is a deficient number, since it is larger than the sum of its proper divisors (1).

28736909 is an equidigital number, since it uses as much as digits as its factorization.

28736909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 163296, while the sum is 44.

The square root of 28736909 is about 5360.6817663428. The cubic root of 28736909 is about 306.2997795522.

The spelling of 28736909 in words is "twenty-eight million, seven hundred thirty-six thousand, nine hundred nine".