21012002222121 has 96 divisors (see below), whose sum is σ = 33384733200000. Its totient is φ = 13160882488320.

The previous prime is 21012002222117. The next prime is 21012002222171. The reversal of 21012002222121 is 12122220021012.

It is a happy number.

21012002222121 is a `hidden beast` number, since 210 + 1 + 20 + 0 + 222 + 212 + 1 = 666.

It is not a de Polignac number, because 21012002222121 - 2² = 21012002222117 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21012002222094 and 21012002222103.

It is not an unprimeable number, because it can be changed into a prime (21012002222111) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 10780913455 + ... + 10780915403.

It is an arithmetic number, because the mean of its divisors is an integer number (347757637500).

Almost surely, 2^{21012002222121} is an apocalyptic number.

It is an amenable number.

21012002222121 is a deficient number, since it is larger than the sum of its proper divisors (12372730977879).

21012002222121 is a wasteful number, since it uses less digits than its factorization.

21012002222121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5221 (or 5209 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21012002222121 its reverse (12122220021012), we get a palindrome (33134222243133).

The spelling of 21012002222121 in words is "twenty-one trillion, twelve billion, two million, two hundred twenty-two thousand, one hundred twenty-one".