21111212021222 has 16 divisors (see below), whose sum is σ = 32759304949440. Its totient is φ = 10191455430912.

The previous prime is 21111212021219. The next prime is 21111212021261. The reversal of 21111212021222 is 22212021211112.

It is a junction number, because it is equal to n+sod(n) for n = 21111212021194 and 21111212021203.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 739523 + ... + 6539825.

It is an arithmetic number, because the mean of its divisors is an integer number (2047456559340).

Almost surely, 2^{21111212021222} is an apocalyptic number.

21111212021222 is a deficient number, since it is larger than the sum of its proper divisors (11648092928218).

21111212021222 is a wasteful number, since it uses less digits than its factorization.

21111212021222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5863087.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 21111212021222 its reverse (22212021211112), we get a palindrome (43323233232334).

The spelling of 21111212021222 in words is "twenty-one trillion, one hundred eleven billion, two hundred twelve million, twenty-one thousand, two hundred twenty-two".