20111222121 has 16 divisors (see below), whose sum is σ = 27627865344. Its totient is φ = 13006079744.

The previous prime is 20111222119. The next prime is 20111222143. The reversal of 20111222121 is 12122211102.

It is a cyclic number.

It is not a de Polignac number, because 20111222121 - 2¹ = 20111222119 is a prime.

It is a super-2 number, since 2×20111222121² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20111222121.

It is not an unprimeable number, because it can be changed into a prime (20111222161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 615186 + ... + 647051.

It is an arithmetic number, because the mean of its divisors is an integer number (1726741584).

Almost surely, 2^20111222121 is an apocalyptic number.

It is an amenable number.

20111222121 is a deficient number, since it is larger than the sum of its proper divisors (7516643223).

20111222121 is a wasteful number, since it uses less digits than its factorization.

20111222121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1262400.

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

Adding to 20111222121 its reverse (12122211102), we get a palindrome (32233433223).

The spelling of 20111222121 in words is "twenty billion, one hundred eleven million, two hundred twenty-two thousand, one hundred twenty-one".