20009844 has 18 divisors (see below), whose sum is σ = 50580530. Its totient is φ = 6669936.

The previous prime is 20009819. The next prime is 20009863. The reversal of 20009844 is 44890002.

It can be written as a sum of positive squares in only one way, i.e., 16160400 + 3849444 = 4020^2 + 1962^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 277879 + ... + 277950.

Almost surely, 2^20009844 is an apocalyptic number.

It is an amenable number.

20009844 is an abundant number, since it is smaller than the sum of its proper divisors (30570686).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20009844 is a wasteful number, since it uses less digits than its factorization.

20009844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 555839 (or 555834 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 20009844 is about 4473.2364122635. The cubic root of 20009844 is about 271.4862888999.

Adding to 20009844 its reverse (44890002), we get a palindrome (64899846).

The spelling of 20009844 in words is "twenty million, nine thousand, eight hundred forty-four".