20206609 has 2 divisors, whose sum is σ = 20206610. Its totient is φ = 20206608.

The previous prime is 20206607. The next prime is 20206631. The reversal of 20206609 is 90660202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18464209 + 1742400 = 4297^2 + 1320^2 .

It is a cyclic number.

It is not a de Polignac number, because 20206609 - 2¹ = 20206607 is a prime.

Together with 20206607, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20206607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10103304 + 10103305.

It is an arithmetic number, because the mean of its divisors is an integer number (10103305).

Almost surely, 2^20206609 is an apocalyptic number.

It is an amenable number.

20206609 is a deficient number, since it is larger than the sum of its proper divisors (1).

20206609 is an equidigital number, since it uses as much as digits as its factorization.

20206609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 20206609 is about 4495.1761923199. The cubic root of 20206609 is about 272.3732665460.

The spelling of 20206609 in words is "twenty million, two hundred six thousand, six hundred nine".