20420442 has 48 divisors (see below), whose sum is σ = 51754560. Its totient is φ = 5697216.

The previous prime is 20420377. The next prime is 20420443. The reversal of 20420442 is 24402402.

20420442 is a `hidden beast` number, since 204 + 20 + 442 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (20420443) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3534 + ... + 7302.

It is an arithmetic number, because the mean of its divisors is an integer number (1078220).

Almost surely, 2^20420442 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20420442, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25877280).

20420442 is an abundant number, since it is smaller than the sum of its proper divisors (31334118).

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

20420442 is a wasteful number, since it uses less digits than its factorization.

20420442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3827 (or 3824 counting only the distinct ones).

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

The square root of 20420442 is about 4518.8983170680. The cubic root of 20420442 is about 273.3306784725.

Adding to 20420442 its reverse (24402402), we get a palindrome (44822844).

The spelling of 20420442 in words is "twenty million, four hundred twenty thousand, four hundred forty-two".