20121122221 has 4 divisors (see below), whose sum is σ = 20179108512. Its totient is φ = 20063135932.

The previous prime is 20121122209. The next prime is 20121122237. The reversal of 20121122221 is 12222112102.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20121122221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20121122195 and 20121122204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121422221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28992625 + ... + 28993318.

It is an arithmetic number, because the mean of its divisors is an integer number (5044777128).

Almost surely, 2^20121122221 is an apocalyptic number.

It is an amenable number.

20121122221 is a deficient number, since it is larger than the sum of its proper divisors (57986291).

20121122221 is an equidigital number, since it uses as much as digits as its factorization.

20121122221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57986290.

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

Adding to 20121122221 its reverse (12222112102), we get a palindrome (32343234323).

The spelling of 20121122221 in words is "twenty billion, one hundred twenty-one million, one hundred twenty-two thousand, two hundred twenty-one".