2121210222121 has 4 divisors (see below), whose sum is σ = 2123968623700. Its totient is φ = 2118451820544.

The previous prime is 2121210222091. The next prime is 2121210222133. The reversal of 2121210222121 is 1212220121212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1552543412121 + 568666810000 = 1246011^2 + 754100^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121210222121 - 2¹⁵ = 2121210189353 is a prime.

It is a super-3 number, since 3×2121210222121³ (a number of 38 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2121210222191) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1379199636 + ... + 1379201173.

It is an arithmetic number, because the mean of its divisors is an integer number (530992155925).

Almost surely, 2^{2121210222121} is an apocalyptic number.

It is an amenable number.

2121210222121 is a deficient number, since it is larger than the sum of its proper divisors (2758401579).

2121210222121 is an equidigital number, since it uses as much as digits as its factorization.

2121210222121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2758401578.

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

Adding to 2121210222121 its reverse (1212220121212), we get a palindrome (3333430343333).

The spelling of 2121210222121 in words is "two trillion, one hundred twenty-one billion, two hundred ten million, two hundred twenty-two thousand, one hundred twenty-one".