213121203333121 has 4 divisors (see below), whose sum is σ = 213121250837572. Its totient is φ = 213121155828672.

The previous prime is 213121203333053. The next prime is 213121203333161. The reversal of 213121203333121 is 121333302121312.

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 98436380523121 + 114684822810000 = 9921511^2 + 10709100^2 .

It is a cyclic number.

It is not a de Polignac number, because 213121203333121 - 2³⁷ = 212983764379649 is a prime.

It is a super-3 number, since 3×213121203333121³ (a number of 44 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 213121203333121.

It is not an unprimeable number, because it can be changed into a prime (213121203333161) 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, 16228260 + ... + 26260213.

It is an arithmetic number, because the mean of its divisors is an integer number (53280312709393).

Almost surely, 2^{213121203333121} is an apocalyptic number.

It is an amenable number.

213121203333121 is a deficient number, since it is larger than the sum of its proper divisors (47504451).

213121203333121 is an equidigital number, since it uses as much as digits as its factorization.

213121203333121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47504450.

The product of its (nonzero) digits is 3888, while the sum is 28.

Adding to 213121203333121 its reverse (121333302121312), we get a palindrome (334454505454433).

The spelling of 213121203333121 in words is "two hundred thirteen trillion, one hundred twenty-one billion, two hundred three million, three hundred thirty-three thousand, one hundred twenty-one".