20056909 has 4 divisors (see below), whose sum is σ = 20131740. Its totient is φ = 19982080.

The previous prime is 20056903. The next prime is 20056961. The reversal of 20056909 is 90965002.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5654884 + 14402025 = 2378^2 + 3795^2 .

It is a cyclic number.

It is not a de Polignac number, because 20056909 - 2⁷ = 20056781 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 (20056903) 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 in 3 ways as a sum of consecutive naturals, for example, 37012 + ... + 37549.

It is an arithmetic number, because the mean of its divisors is an integer number (5032935).

Almost surely, 2^20056909 is an apocalyptic number.

It is an amenable number.

20056909 is a deficient number, since it is larger than the sum of its proper divisors (74831).

20056909 is an equidigital number, since it uses as much as digits as its factorization.

20056909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74830.

The product of its (nonzero) digits is 4860, while the sum is 31.

The square root of 20056909 is about 4478.4940549252. The cubic root of 20056909 is about 271.6989758371.

The spelling of 20056909 in words is "twenty million, fifty-six thousand, nine hundred nine".