21211112212 has 12 divisors (see below), whose sum is σ = 37486966356. Its totient is φ = 10500550400.

The previous prime is 21211112207. The next prime is 21211112231. The reversal of 21211112212 is 21221111212.

It can be written as a sum of positive squares in 2 ways, for example, as 12552065296 + 8659046916 = 112036^2 + 93054^2 .

It is a super-2 number, since 2×21211112212² (a number of 21 digits) contains 22 as substring.

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 in 3 ways as a sum of consecutive naturals, for example, 26250973 + ... + 26251780.

It is an arithmetic number, because the mean of its divisors is an integer number (3123913863).

Almost surely, 2^21211112212 is an apocalyptic number.

It is an amenable number.

21211112212 is a deficient number, since it is larger than the sum of its proper divisors (16275854144).

21211112212 is a wasteful number, since it uses less digits than its factorization.

21211112212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52502858 (or 52502856 counting only the distinct ones).

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

Adding to 21211112212 its reverse (21221111212), we get a palindrome (42432223424).

The spelling of 21211112212 in words is "twenty-one billion, two hundred eleven million, one hundred twelve thousand, two hundred twelve".