21111122221212 has 48 divisors (see below), whose sum is σ = 50841862888320. Its totient is φ = 6814518566592.

The previous prime is 21111122221201. The next prime is 21111122221223. The reversal of 21111122221212 is 21212222111112.

It is an interprime number because it is at equal distance from previous prime (21111122221201) and next prime (21111122221223).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 222474723 + ... + 222569594.

It is an arithmetic number, because the mean of its divisors is an integer number (1059205476840).

Almost surely, 2^{21111122221212} is an apocalyptic number.

It is an amenable number.

21111122221212 is an abundant number, since it is smaller than the sum of its proper divisors (29730740667108).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21111122221212 is a wasteful number, since it uses less digits than its factorization.

21111122221212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 445044450 (or 445044448 counting only the distinct ones).

The product of its digits is 128, while the sum is 21.

Adding to 21111122221212 its reverse (21212222111112), we get a palindrome (42323344332324).

The spelling of 21111122221212 in words is "twenty-one trillion, one hundred eleven billion, one hundred twenty-two million, two hundred twenty-one thousand, two hundred twelve".