21424222420 has 12 divisors (see below), whose sum is σ = 44990867124. Its totient is φ = 8569688960.

The previous prime is 21424222399. The next prime is 21424222423. The reversal of 21424222420 is 2422242412.

It can be written as a sum of positive squares in 2 ways, for example, as 9450172944 + 11974049476 = 97212^2 + 109426^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21424222423) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 535605541 + ... + 535605580.

It is an arithmetic number, because the mean of its divisors is an integer number (3749238927).

Almost surely, 2^21424222420 is an apocalyptic number.

21424222420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21424222420 is an abundant number, since it is smaller than the sum of its proper divisors (23566644704).

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

21424222420 is a wasteful number, since it uses less digits than its factorization.

21424222420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1071211130 (or 1071211128 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 25.

Adding to 21424222420 its reverse (2422242412), we get a palindrome (23846464832).

The spelling of 21424222420 in words is "twenty-one billion, four hundred twenty-four million, two hundred twenty-two thousand, four hundred twenty".