21222212012021 has 4 divisors (see below), whose sum is σ = 21222270860352. Its totient is φ = 21222153163692.

The previous prime is 21222212011991. The next prime is 21222212012123. The reversal of 21222212012021 is 12021021222212.

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 21222212012021 - 2¹⁰ = 21222212010997 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21222212011984 and 21222212012002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222212014021) 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, 28879871 + ... + 29605596.

It is an arithmetic number, because the mean of its divisors is an integer number (5305567715088).

Almost surely, 2^{21222212012021} is an apocalyptic number.

It is an amenable number.

21222212012021 is a deficient number, since it is larger than the sum of its proper divisors (58848331).

21222212012021 is an equidigital number, since it uses as much as digits as its factorization.

21222212012021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58848330.

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 21222212012021 its reverse (12021021222212), we get a palindrome (33243233234233).

The spelling of 21222212012021 in words is "twenty-one trillion, two hundred twenty-two billion, two hundred twelve million, twelve thousand, twenty-one".