21222211212021 has 24 divisors (see below), whose sum is σ = 30568149001440. Its totient is φ = 13090204026112.

The previous prime is 21222211212001. The next prime is 21222211212023. The reversal of 21222211212021 is 12021211222212.

It is not a de Polignac number, because 21222211212021 - 2¹¹ = 21222211209973 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222211212023) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 207387426 + ... + 207489731.

It is an arithmetic number, because the mean of its divisors is an integer number (1273672875060).

Almost surely, 2^{21222211212021} is an apocalyptic number.

It is an amenable number.

21222211212021 is a deficient number, since it is larger than the sum of its proper divisors (9345937789419).

21222211212021 is a wasteful number, since it uses less digits than its factorization.

21222211212021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414877253 (or 414877236 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 21.

Adding to 21222211212021 its reverse (12021211222212), we get a palindrome (33243422434233).

The spelling of 21222211212021 in words is "twenty-one trillion, two hundred twenty-two billion, two hundred eleven million, two hundred twelve thousand, twenty-one".