21202121021212 has 12 divisors (see below), whose sum is σ = 37103768822736. Its totient is φ = 10601044214720.

The previous prime is 21202121021203. The next prime is 21202121021231. The reversal of 21202121021212 is 21212012120212.

It is a self number, because there is not a number n which added to its sum of digits gives 21202121021212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 865864 + ... + 6569167.

It is an arithmetic number, because the mean of its divisors is an integer number (3091980735228).

Almost surely, 2^{21202121021212} is an apocalyptic number.

It is an amenable number.

21202121021212 is a deficient number, since it is larger than the sum of its proper divisors (15901647801524).

21202121021212 is a wasteful number, since it uses less digits than its factorization.

21202121021212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8147948 (or 8147946 counting only the distinct ones).

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

Adding to 21202121021212 its reverse (21212012120212), we get a palindrome (42414133141424).

The spelling of 21202121021212 in words is "twenty-one trillion, two hundred two billion, one hundred twenty-one million, twenty-one thousand, two hundred twelve".