21200222122021 has 4 divisors (see below), whose sum is σ = 21200231369632. Its totient is φ = 21200212874412.

The previous prime is 21200222122019. The next prime is 21200222122081. The reversal of 21200222122021 is 12022122200212.

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 21200222122021 - 2¹ = 21200222122019 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21200222122021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200222122081) 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, 1676656 + ... + 6723958.

It is an arithmetic number, because the mean of its divisors is an integer number (5300057842408).

Almost surely, 2^{21200222122021} is an apocalyptic number.

It is an amenable number.

21200222122021 is a deficient number, since it is larger than the sum of its proper divisors (9247611).

21200222122021 is an equidigital number, since it uses as much as digits as its factorization.

21200222122021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9247610.

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 21200222122021 its reverse (12022122200212), we get a palindrome (33222344322233).

The spelling of 21200222122021 in words is "twenty-one trillion, two hundred billion, two hundred twenty-two million, one hundred twenty-two thousand, twenty-one".