21234442330021 has 4 divisors (see below), whose sum is σ = 21234461687712. Its totient is φ = 21234422972332.

The previous prime is 21234442329949. The next prime is 21234442330069. The reversal of 21234442330021 is 12003324443212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21234442330021 - 2²⁵ = 21234408775589 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21234442330091) 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, 7927825 + ... + 10262518.

It is an arithmetic number, because the mean of its divisors is an integer number (5308615421928).

Almost surely, 2^{21234442330021} is an apocalyptic number.

It is an amenable number.

21234442330021 is a deficient number, since it is larger than the sum of its proper divisors (19357691).

21234442330021 is a wasteful number, since it uses less digits than its factorization.

21234442330021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19357690.

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

Adding to 21234442330021 its reverse (12003324443212), we get a palindrome (33237766773233).

The spelling of 21234442330021 in words is "twenty-one trillion, two hundred thirty-four billion, four hundred forty-two million, three hundred thirty thousand, twenty-one".