21242144400420 has 48 divisors (see below), whose sum is σ = 60146296519680. Its totient is φ = 5600924964096.

The previous prime is 21242144400401. The next prime is 21242144400427. The reversal of 21242144400420 is 2400444124212.

It is a super-2 number, since 2×21242144400420² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (21242144400427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1988959492 + ... + 1988970171.

It is an arithmetic number, because the mean of its divisors is an integer number (1253047844160).

Almost surely, 2^{21242144400420} is an apocalyptic number.

21242144400420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21242144400420 is an abundant number, since it is smaller than the sum of its proper divisors (38904152119260).

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

21242144400420 is a wasteful number, since it uses less digits than its factorization.

21242144400420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3977929764 (or 3977929762 counting only the distinct ones).

The product of its (nonzero) digits is 16384, while the sum is 30.

Adding to 21242144400420 its reverse (2400444124212), we get a palindrome (23642588524632).

The spelling of 21242144400420 in words is "twenty-one trillion, two hundred forty-two billion, one hundred forty-four million, four hundred thousand, four hundred twenty".