20442420 has 54 divisors (see below), whose sum is σ = 62193222. Its totient is φ = 5435136.

The previous prime is 20442413. The next prime is 20442427. The reversal of 20442420 is 2424402.

20442420 is a `hidden beast` number, since 204 + 42 + 420 = 666.

It is an interprime number because it is at equal distance from previous prime (20442413) and next prime (20442427).

It can be written as a sum of positive squares in 3 ways, for example, as 138384 + 20304036 = 372^2 + 4506^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 20442393 and 20442402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20442427) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 60492 + ... + 60828.

Almost surely, 2^20442420 is an apocalyptic number.

20442420 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 20442420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31096611).

20442420 is an abundant number, since it is smaller than the sum of its proper divisors (41750802).

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

20442420 is a wasteful number, since it uses less digits than its factorization.

20442420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 689 (or 347 counting only the distinct ones).

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

The square root of 20442420 is about 4521.3294505046. The cubic root of 20442420 is about 273.4287029224.

Adding to 20442420 its reverse (2424402), we get a palindrome (22866822).

It can be divided in two parts, 204 and 42420, that added together give a palindrome (42624).

The spelling of 20442420 in words is "twenty million, four hundred forty-two thousand, four hundred twenty".