28561691 has 2 divisors, whose sum is σ = 28561692. Its totient is φ = 28561690.

The previous prime is 28561679. The next prime is 28561727. The reversal of 28561691 is 19616582.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28561691 - 2⁶ = 28561627 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28560691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14280845 + 14280846.

It is an arithmetic number, because the mean of its divisors is an integer number (14280846).

Almost surely, 2^28561691 is an apocalyptic number.

28561691 is a deficient number, since it is larger than the sum of its proper divisors (1).

28561691 is an equidigital number, since it uses as much as digits as its factorization.

28561691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25920, while the sum is 38.

The square root of 28561691 is about 5344.3138942244. The cubic root of 28561691 is about 305.6759745215.

The spelling of 28561691 in words is "twenty-eight million, five hundred sixty-one thousand, six hundred ninety-one".