20440404 has 48 divisors (see below), whose sum is σ = 54008640. Its totient is φ = 6683040.

The previous prime is 20440397. The next prime is 20440421. The reversal of 20440404 is 40404402.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3939 + ... + 7509.

It is an arithmetic number, because the mean of its divisors is an integer number (1125180).

Almost surely, 2^20440404 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20440404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27004320).

20440404 is an abundant number, since it is smaller than the sum of its proper divisors (33568236).

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

20440404 is a wasteful number, since it uses less digits than its factorization.

20440404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3637 (or 3629 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 18.

The square root of 20440404 is about 4521.1065017316. The cubic root of 20440404 is about 273.4197142543.

Adding to 20440404 its reverse (40404402), we get a palindrome (60844806).

The spelling of 20440404 in words is "twenty million, four hundred forty thousand, four hundred four".