2121012201221 has 4 divisors (see below), whose sum is σ = 2121015213612. Its totient is φ = 2121009188832.

The previous prime is 2121012201211. The next prime is 2121012201227. The reversal of 2121012201221 is 1221022101212.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 216211980196 + 1904800221025 = 464986^2 + 1380145^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121012201221 - 2²² = 2121008006917 is a prime.

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 2121012201221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121012201227) 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 3 ways as a sum of consecutive naturals, for example, 176795 + ... + 2067191.

It is an arithmetic number, because the mean of its divisors is an integer number (530253803403).

Almost surely, 2^{2121012201221} is an apocalyptic number.

It is an amenable number.

2121012201221 is a deficient number, since it is larger than the sum of its proper divisors (3012391).

2121012201221 is a wasteful number, since it uses less digits than its factorization.

2121012201221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3012390.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 2121012201221 its reverse (1221022101212), we get a palindrome (3342034302433).

The spelling of 2121012201221 in words is "two trillion, one hundred twenty-one billion, twelve million, two hundred one thousand, two hundred twenty-one".