2121220212121 has 8 divisors (see below), whose sum is σ = 2233229486400. Its totient is φ = 2009247548400.

The previous prime is 2121220212113. The next prime is 2121220212131. The reversal of 2121220212121 is 1212120221212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2121220212121 - 2³ = 2121220212113 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2121220212131) 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 7 ways as a sum of consecutive naturals, for example, 9033661 + ... + 9265498.

It is an arithmetic number, because the mean of its divisors is an integer number (279153685800).

Almost surely, 2^{2121220212121} is an apocalyptic number.

It is an amenable number.

2121220212121 is a deficient number, since it is larger than the sum of its proper divisors (112009274279).

2121220212121 is a wasteful number, since it uses less digits than its factorization.

2121220212121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18305279.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 2121220212121 its reverse (1212120221212), we get a palindrome (3333340433333).

Subtracting from 2121220212121 its reverse (1212120221212), we obtain a palindrome (909099990909).

The spelling of 2121220212121 in words is "two trillion, one hundred twenty-one billion, two hundred twenty million, two hundred twelve thousand, one hundred twenty-one".