20121112221 has 16 divisors (see below), whose sum is σ = 30705136128. Its totient is φ = 11481130800.

The previous prime is 20121112213. The next prime is 20121112223. The reversal of 20121112221 is 12221112102.

It is not a de Polignac number, because 20121112221 - 2³ = 20121112213 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20121112221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121112223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 678795 + ... + 707816.

It is an arithmetic number, because the mean of its divisors is an integer number (1919071008).

Almost surely, 2^20121112221 is an apocalyptic number.

20121112221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20121112221 is a deficient number, since it is larger than the sum of its proper divisors (10584023907).

20121112221 is a wasteful number, since it uses less digits than its factorization.

20121112221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1387312.

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

Adding to 20121112221 its reverse (12221112102), we get a palindrome (32342224323).

The spelling of 20121112221 in words is "twenty billion, one hundred twenty-one million, one hundred twelve thousand, two hundred twenty-one".