21222102021 has 4 divisors (see below), whose sum is σ = 28296136032. Its totient is φ = 14148068012.

The previous prime is 21222101987. The next prime is 21222102023. The reversal of 21222102021 is 12020122212.

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 21222102021 - 2¹¹ = 21222099973 is a prime.

It is a super-2 number, since 2×21222102021² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222102023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3537017001 + ... + 3537017006.

It is an arithmetic number, because the mean of its divisors is an integer number (7074034008).

Almost surely, 2^21222102021 is an apocalyptic number.

It is an amenable number.

21222102021 is a deficient number, since it is larger than the sum of its proper divisors (7074034011).

21222102021 is an equidigital number, since it uses as much as digits as its factorization.

21222102021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7074034010.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21222102021 its reverse (12020122212), we get a palindrome (33242224233).

The spelling of 21222102021 in words is "twenty-one billion, two hundred twenty-two million, one hundred two thousand, twenty-one".