20440420 has 96 divisors (see below), whose sum is σ = 57689856. Its totient is φ = 5875200.

The previous prime is 20440397. The next prime is 20440421. The reversal of 20440420 is 2404402.

It is a junction number, because it is equal to n+sod(n) for n = 20440394 and 20440403.

It is not an unprimeable number, because it can be changed into a prime (20440421) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19510 + ... + 20530.

It is an arithmetic number, because the mean of its divisors is an integer number (600936).

Almost surely, 2^20440420 is an apocalyptic number.

20440420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20440420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28844928).

20440420 is an abundant number, since it is smaller than the sum of its proper divisors (37249436).

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

20440420 is a wasteful number, since it uses less digits than its factorization.

20440420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1061 (or 1059 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 16.

The square root of 20440420 is about 4521.1082712096. The cubic root of 20440420 is about 273.4197855953.

Adding to 20440420 its reverse (2404402), we get a palindrome (22844822).

The spelling of 20440420 in words is "twenty million, four hundred forty thousand, four hundred twenty".