21120222121 has 12 divisors (see below), whose sum is σ = 22462227648. Its totient is φ = 19820722064.

The previous prime is 21120222043. The next prime is 21120222133. The reversal of 21120222121 is 12122202112.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-21120222121 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21120222095 and 21120222104.

It is not an unprimeable number, because it can be changed into a prime (21120222161) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 98845 + ... + 228058.

It is an arithmetic number, because the mean of its divisors is an integer number (1871852304).

Almost surely, 2^21120222121 is an apocalyptic number.

It is an amenable number.

21120222121 is a deficient number, since it is larger than the sum of its proper divisors (1342005527).

21120222121 is an equidigital number, since it uses as much as digits as its factorization.

21120222121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 327032 (or 326979 counting only the distinct ones).

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

Adding to 21120222121 its reverse (12122202112), we get a palindrome (33242424233).

The spelling of 21120222121 in words is "twenty-one billion, one hundred twenty million, two hundred twenty-two thousand, one hundred twenty-one".