21212212212212 has 24 divisors (see below), whose sum is σ = 42510828575040. Its totient is φ = 9072432915840.

The previous prime is 21212212212211. The next prime is 21212212212239. The reversal of 21212212212212 is 21221221221212.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212212212211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 771451637 + ... + 771479132.

It is an arithmetic number, because the mean of its divisors is an integer number (1771284523960).

Almost surely, 2^{21212212212212} is an apocalyptic number.

It is an amenable number.

21212212212212 is an abundant number, since it is smaller than the sum of its proper divisors (21298616362828).

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

21212212212212 is a wasteful number, since it uses less digits than its factorization.

21212212212212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1542931271 (or 1542931269 counting only the distinct ones).

The product of its digits is 512, while the sum is 23.

Adding to 21212212212212 its reverse (21221221221212), we get a palindrome (42433433433424).

The spelling of 21212212212212 in words is "twenty-one trillion, two hundred twelve billion, two hundred twelve million, two hundred twelve thousand, two hundred twelve".