20606909 has 4 divisors (see below), whose sum is σ = 21271680. Its totient is φ = 19942140.

The previous prime is 20606899. The next prime is 20606917. The reversal of 20606909 is 90960602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20606909 - 2¹⁶ = 20541373 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20606939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 332339 + ... + 332400.

It is an arithmetic number, because the mean of its divisors is an integer number (5317920).

Almost surely, 2^20606909 is an apocalyptic number.

It is an amenable number.

20606909 is a deficient number, since it is larger than the sum of its proper divisors (664771).

20606909 is an equidigital number, since it uses as much as digits as its factorization.

20606909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 664770.

The product of its (nonzero) digits is 5832, while the sum is 32.

The square root of 20606909 is about 4539.4833406457. The cubic root of 20606909 is about 274.1601218349.

The spelling of 20606909 in words is "twenty million, six hundred six thousand, nine hundred nine".