20131221212 has 6 divisors (see below), whose sum is σ = 35229637128. Its totient is φ = 10065610604.

The previous prime is 20131221199. The next prime is 20131221241. The reversal of 20131221212 is 21212213102.

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, 2516402648 + ... + 2516402655.

It is an arithmetic number, because the mean of its divisors is an integer number (5871606188).

Almost surely, 2^20131221212 is an apocalyptic number.

It is an amenable number.

20131221212 is a deficient number, since it is larger than the sum of its proper divisors (15098415916).

20131221212 is a wasteful number, since it uses less digits than its factorization.

20131221212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5032805307 (or 5032805305 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 20131221212 its reverse (21212213102), we get a palindrome (41343434314).

The spelling of 20131221212 in words is "twenty billion, one hundred thirty-one million, two hundred twenty-one thousand, two hundred twelve".