28811609 has 2 divisors, whose sum is σ = 28811610. Its totient is φ = 28811608.

The previous prime is 28811603. The next prime is 28811621. The reversal of 28811609 is 90611882.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24970009 + 3841600 = 4997^2 + 1960^2 .

It is a cyclic number.

It is not a de Polignac number, because 28811609 - 2²⁰ = 27763033 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28811603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14405804 + 14405805.

It is an arithmetic number, because the mean of its divisors is an integer number (14405805).

Almost surely, 2^28811609 is an apocalyptic number.

It is an amenable number.

28811609 is a deficient number, since it is larger than the sum of its proper divisors (1).

28811609 is an equidigital number, since it uses as much as digits as its factorization.

28811609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6912, while the sum is 35.

The square root of 28811609 is about 5367.6446417400. The cubic root of 28811609 is about 306.5649530091.

The spelling of 28811609 in words is "twenty-eight million, eight hundred eleven thousand, six hundred nine".