21011222120212 has 6 divisors (see below), whose sum is σ = 36769638710378. Its totient is φ = 10505611060104.

The previous prime is 21011222120201. The next prime is 21011222120233. The reversal of 21011222120212 is 21202122211012.

It can be written as a sum of positive squares in only one way, i.e., 11780587185796 + 9230634934416 = 3432286^2 + 3038196^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21011222120212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2626402765023 + ... + 2626402765030.

Almost surely, 2^{21011222120212} is an apocalyptic number.

It is an amenable number.

21011222120212 is a deficient number, since it is larger than the sum of its proper divisors (15758416590166).

21011222120212 is a wasteful number, since it uses less digits than its factorization.

21011222120212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5252805530057 (or 5252805530055 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21011222120212 its reverse (21202122211012), we get a palindrome (42213344331224).

The spelling of 21011222120212 in words is "twenty-one trillion, eleven billion, two hundred twenty-two million, one hundred twenty thousand, two hundred twelve".