20108609 has 2 divisors, whose sum is σ = 20108610. Its totient is φ = 20108608.

The previous prime is 20108597. The next prime is 20108623. The reversal of 20108609 is 90680102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14227984 + 5880625 = 3772^2 + 2425^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20108609 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20108009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10054304 + 10054305.

It is an arithmetic number, because the mean of its divisors is an integer number (10054305).

Almost surely, 2^20108609 is an apocalyptic number.

It is an amenable number.

20108609 is a deficient number, since it is larger than the sum of its proper divisors (1).

20108609 is an equidigital number, since it uses as much as digits as its factorization.

20108609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 20108609 is about 4484.2623696657. The cubic root of 20108609 is about 271.9322252202.

The spelling of 20108609 in words is "twenty million, one hundred eight thousand, six hundred nine".