21112112212 has 6 divisors (see below), whose sum is σ = 36946196378. Its totient is φ = 10556056104.

The previous prime is 21112112173. The next prime is 21112112237. The reversal of 21112112212 is 21221121112.

It can be written as a sum of positive squares in only one way, i.e., 19109191696 + 2002920516 = 138236^2 + 44754^2 .

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 as a sum of consecutive naturals, namely, 2639014023 + ... + 2639014030.

Almost surely, 2^21112112212 is an apocalyptic number.

It is an amenable number.

21112112212 is a deficient number, since it is larger than the sum of its proper divisors (15834084166).

21112112212 is a wasteful number, since it uses less digits than its factorization.

21112112212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5278028057 (or 5278028055 counting only the distinct ones).

The product of its digits is 32, while the sum is 16.

Adding to 21112112212 its reverse (21221121112), we get a palindrome (42333233324).

The spelling of 21112112212 in words is "twenty-one billion, one hundred twelve million, one hundred twelve thousand, two hundred twelve".