21421334443 has 4 divisors (see below), whose sum is σ = 21429381168. Its totient is φ = 21413287720.

The previous prime is 21421334419. The next prime is 21421334453. The reversal of 21421334443 is 34443312412.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21421334443 - 2³³ = 12831399851 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21421334453) 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, 4019368 + ... + 4024693.

It is an arithmetic number, because the mean of its divisors is an integer number (5357345292).

Almost surely, 2^21421334443 is an apocalyptic number.

21421334443 is a deficient number, since it is larger than the sum of its proper divisors (8046725).

21421334443 is an equidigital number, since it uses as much as digits as its factorization.

21421334443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8046724.

The product of its digits is 27648, while the sum is 31.

Adding to 21421334443 its reverse (34443312412), we get a palindrome (55864646855).

The spelling of 21421334443 in words is "twenty-one billion, four hundred twenty-one million, three hundred thirty-four thousand, four hundred forty-three".