20121221108 has 12 divisors (see below), whose sum is σ = 35436419172. Its totient is φ = 9996529920.

The previous prime is 20121221041. The next prime is 20121221117. The reversal of 20121221108 is 80112212102.

It can be written as a sum of positive squares in 2 ways, for example, as 6511198864 + 13610022244 = 80692^2 + 116662^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20121221108.

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, 16019453 + ... + 16020708.

It is an arithmetic number, because the mean of its divisors is an integer number (2953034931).

Almost surely, 2^20121221108 is an apocalyptic number.

It is an amenable number.

20121221108 is a deficient number, since it is larger than the sum of its proper divisors (15315198064).

20121221108 is a wasteful number, since it uses less digits than its factorization.

20121221108 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32040322 (or 32040320 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 20.

The spelling of 20121221108 in words is "twenty billion, one hundred twenty-one million, two hundred twenty-one thousand, one hundred eight".