21421443344 has 40 divisors (see below), whose sum is σ = 47442463488. Its totient is φ = 9178824960.

The previous prime is 21421443341. The next prime is 21421443347. The reversal of 21421443344 is 44334412412.

It is an interprime number because it is at equal distance from previous prime (21421443341) and next prime (21421443347).

It is a self number, because there is not a number n which added to its sum of digits gives 21421443344.

It is not an unprimeable number, because it can be changed into a prime (21421443341) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 669929 + ... + 701175.

Almost surely, 2^21421443344 is an apocalyptic number.

It is an amenable number.

21421443344 is an abundant number, since it is smaller than the sum of its proper divisors (26021020144).

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

21421443344 is a wasteful number, since it uses less digits than its factorization.

21421443344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37383 (or 37377 counting only the distinct ones).

The product of its digits is 36864, while the sum is 32.

Adding to 21421443344 its reverse (44334412412), we get a palindrome (65755855756).

The spelling of 21421443344 in words is "twenty-one billion, four hundred twenty-one million, four hundred forty-three thousand, three hundred forty-four".