20121221312 has 56 divisors (see below), whose sum is σ = 42657003840. Its totient is φ = 9388811520.

The previous prime is 20121221311. The next prime is 20121221327. The reversal of 20121221312 is 21312212102.

It is not an unprimeable number, because it can be changed into a prime (20121221311) 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, 42014 + ... + 204957.

Almost surely, 2^20121221312 is an apocalyptic number.

It is an amenable number.

20121221312 is an abundant number, since it is smaller than the sum of its proper divisors (22535782528).

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

20121221312 is a wasteful number, since it uses less digits than its factorization.

20121221312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247069 (or 247059 counting only the distinct ones).

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

Adding to 20121221312 its reverse (21312212102), we get a palindrome (41433433414).

The spelling of 20121221312 in words is "twenty billion, one hundred twenty-one million, two hundred twenty-one thousand, three hundred twelve".