21334441021 has 4 divisors (see below), whose sum is σ = 21335017500. Its totient is φ = 21333864544.

The previous prime is 21334440961. The next prime is 21334441043. The reversal of 21334441021 is 12014443312.

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

It can be written as a sum of positive squares in 2 ways, for example, as 13609788921 + 7724652100 = 116661^2 + 87890^2 .

It is a cyclic number.

It is not a de Polignac number, because 21334441021 - 2¹⁵ = 21334408253 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 (21334441081) 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, 228616 + ... + 308113.

It is an arithmetic number, because the mean of its divisors is an integer number (5333754375).

Almost surely, 2^21334441021 is an apocalyptic number.

It is an amenable number.

21334441021 is a deficient number, since it is larger than the sum of its proper divisors (576479).

21334441021 is an equidigital number, since it uses as much as digits as its factorization.

21334441021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 576478.

The product of its (nonzero) digits is 2304, while the sum is 25.

Adding to 21334441021 its reverse (12014443312), we get a palindrome (33348884333).

The spelling of 21334441021 in words is "twenty-one billion, three hundred thirty-four million, four hundred forty-one thousand, twenty-one".