20620909 has 16 divisors (see below), whose sum is σ = 22538880. Its totient is φ = 18800640.

The previous prime is 20620891. The next prime is 20620927. The reversal of 20620909 is 90902602.

It is an interprime number because it is at equal distance from previous prime (20620891) and next prime (20620927).

It is a cyclic number.

It is not a de Polignac number, because 20620909 - 2¹³ = 20612717 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 (20620109) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 80109 + ... + 80365.

It is an arithmetic number, because the mean of its divisors is an integer number (1408680).

Almost surely, 2^20620909 is an apocalyptic number.

It is an amenable number.

20620909 is a deficient number, since it is larger than the sum of its proper divisors (1917971).

20620909 is a wasteful number, since it uses less digits than its factorization.

20620909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 420.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 20620909 is about 4541.0251045331. The cubic root of 20620909 is about 274.2221944278. Note that the first 3 decimals are identical.

It can be divided in two parts, 206 and 20909, that added together give a triangular number (21115 = T₂₀₅).

The spelling of 20620909 in words is "twenty million, six hundred twenty thousand, nine hundred nine".