20950409 has 4 divisors (see below), whose sum is σ = 22182804. Its totient is φ = 19718016.

The previous prime is 20950403. The next prime is 20950411. The reversal of 20950409 is 90405902.

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 10368400 + 10582009 = 3220^2 + 3253^2 .

It is a cyclic number.

It is not a de Polignac number, because 20950409 - 2⁴ = 20950393 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (20950403) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 616172 + ... + 616205.

It is an arithmetic number, because the mean of its divisors is an integer number (5545701).

Almost surely, 2^20950409 is an apocalyptic number.

It is an amenable number.

20950409 is a deficient number, since it is larger than the sum of its proper divisors (1232395).

20950409 is a wasteful number, since it uses less digits than its factorization.

20950409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1232394.

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 20950409 is about 4577.1616750995. The cubic root of 20950409 is about 275.6750753402.

The spelling of 20950409 in words is "twenty million, nine hundred fifty thousand, four hundred nine".