21111202222212 has 72 divisors (see below), whose sum is σ = 52322191082784. Its totient is φ = 6602222724608.

The previous prime is 21111202222171. The next prime is 21111202222217. The reversal of 21111202222212 is 21222220211112.

It is not an unprimeable number, because it can be changed into a prime (21111202222217) 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, 19984843 + ... + 21014669.

It is an arithmetic number, because the mean of its divisors is an integer number (726697098372).

Almost surely, 2^{21111202222212} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21111202222212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26161095541392).

21111202222212 is an abundant number, since it is smaller than the sum of its proper divisors (31210988860572).

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

21111202222212 is a wasteful number, since it uses less digits than its factorization.

21111202222212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1030485 (or 1030166 counting only the distinct ones).

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

Adding to 21111202222212 its reverse (21222220211112), we get a palindrome (42333422433324).

The spelling of 21111202222212 in words is "twenty-one trillion, one hundred eleven billion, two hundred two million, two hundred twenty-two thousand, two hundred twelve".