21131032233221 has 4 divisors (see below), whose sum is σ = 21131042477952. Its totient is φ = 21131021988492.

The previous prime is 21131032233209. The next prime is 21131032233247. The reversal of 21131032233221 is 12233223013112.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21131032233221 - 2¹⁰ = 21131032232197 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 (21131032239221) 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, 828815 + ... + 6553548.

It is an arithmetic number, because the mean of its divisors is an integer number (5282760619488).

Almost surely, 2^{21131032233221} is an apocalyptic number.

It is an amenable number.

21131032233221 is a deficient number, since it is larger than the sum of its proper divisors (10244731).

21131032233221 is an equidigital number, since it uses as much as digits as its factorization.

21131032233221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10244730.

The product of its (nonzero) digits is 2592, while the sum is 26.

Adding to 21131032233221 its reverse (12233223013112), we get a palindrome (33364255246333).

The spelling of 21131032233221 in words is "twenty-one trillion, one hundred thirty-one billion, thirty-two million, two hundred thirty-three thousand, two hundred twenty-one".