2121201015221 has 2 divisors, whose sum is σ = 2121201015222. Its totient is φ = 2121201015220.

The previous prime is 2121201015209. The next prime is 2121201015229. The reversal of 2121201015221 is 1225101021212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1691271639121 + 429929376100 = 1300489^2 + 655690^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2121201015221 is a prime.

It is a super-4 number, since 4×2121201015221⁴ (a number of 50 digits) contains 4444 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 2121201015193 and 2121201015202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121201015229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060600507610 + 1060600507611.

It is an arithmetic number, because the mean of its divisors is an integer number (1060600507611).

Almost surely, 2^{2121201015221} is an apocalyptic number.

It is an amenable number.

2121201015221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121201015221 is an equidigital number, since it uses as much as digits as its factorization.

2121201015221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 160, while the sum is 20.

Adding to 2121201015221 its reverse (1225101021212), we get a palindrome (3346302036433).

The spelling of 2121201015221 in words is "two trillion, one hundred twenty-one billion, two hundred one million, fifteen thousand, two hundred twenty-one".