21000121222222 has 16 divisors (see below), whose sum is σ = 33354485860752. Its totient is φ = 9882009348480.

The previous prime is 21000121222217. The next prime is 21000121222237. The reversal of 21000121222222 is 22222212100012.

It is a self number, because there is not a number n which added to its sum of digits gives 21000121222222.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11668113 + ... + 13347100.

It is an arithmetic number, because the mean of its divisors is an integer number (2084655366297).

Almost surely, 2^{21000121222222} is an apocalyptic number.

21000121222222 is a deficient number, since it is larger than the sum of its proper divisors (12354364638530).

21000121222222 is a wasteful number, since it uses less digits than its factorization.

21000121222222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25039923.

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

Adding to 21000121222222 its reverse (22222212100012), we get a palindrome (43222333322234).

The spelling of 21000121222222 in words is "twenty-one trillion, one hundred twenty-one million, two hundred twenty-two thousand, two hundred twenty-two".