21211212012 has 24 divisors (see below), whose sum is σ = 50331691200. Its totient is φ = 6950566416.

The previous prime is 21211211969. The next prime is 21211212017. The reversal of 21211212012 is 21021211212.

It is a junction number, because it is equal to n+sod(n) for n = 21211211982 and 21211212000.

It is not an unprimeable number, because it can be changed into a prime (21211212017) 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, 14978962 + ... + 14980377.

It is an arithmetic number, because the mean of its divisors is an integer number (2097153800).

Almost surely, 2^21211212012 is an apocalyptic number.

It is an amenable number.

21211212012 is an abundant number, since it is smaller than the sum of its proper divisors (29120479188).

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

21211212012 is a wasteful number, since it uses less digits than its factorization.

21211212012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29959405 (or 29959403 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21211212012 its reverse (21021211212), we get a palindrome (42232423224).

The spelling of 21211212012 in words is "twenty-one billion, two hundred eleven million, two hundred twelve thousand, twelve".