20121221104 has 40 divisors (see below), whose sum is σ = 39587153760. Its totient is φ = 9906124800.

The previous prime is 20121221041. The next prime is 20121221117. The reversal of 20121221104 is 40112212102.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 313869 + ... + 372499.

It is an arithmetic number, because the mean of its divisors is an integer number (989678844).

Almost surely, 2^20121221104 is an apocalyptic number.

It is an amenable number.

20121221104 is a deficient number, since it is larger than the sum of its proper divisors (19465932656).

20121221104 is a wasteful number, since it uses less digits than its factorization.

20121221104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58969 (or 58963 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 20121221104 its reverse (40112212102), we get a palindrome (60233433206).

The spelling of 20121221104 in words is "twenty billion, one hundred twenty-one million, two hundred twenty-one thousand, one hundred four".