21013322221 has 4 divisors (see below), whose sum is σ = 21014539200. Its totient is φ = 21012105244.

The previous prime is 21013322203. The next prime is 21013322233. The reversal of 21013322221 is 12222331012.

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 21013322221 - 2⁵ = 21013322189 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 (21013322201) 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, 582211 + ... + 617248.

It is an arithmetic number, because the mean of its divisors is an integer number (5253634800).

Almost surely, 2^21013322221 is an apocalyptic number.

It is an amenable number.

21013322221 is a deficient number, since it is larger than the sum of its proper divisors (1216979).

21013322221 is a wasteful number, since it uses less digits than its factorization.

21013322221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1216978.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21013322221 its reverse (12222331012), we get a palindrome (33235653233).

The spelling of 21013322221 in words is "twenty-one billion, thirteen million, three hundred twenty-two thousand, two hundred twenty-one".