20012120201221 has 2 divisors, whose sum is σ = 20012120201222. Its totient is φ = 20012120201220.

The previous prime is 20012120201201. The next prime is 20012120201279. The reversal of 20012120201221 is 12210202121002.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20003658777025 + 8461424196 = 4472545^2 + 91986^2 .

It is a cyclic number.

It is not a de Polignac number, because 20012120201221 - 2⁷ = 20012120201093 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20012120201195 and 20012120201204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20012120201201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10006060100610 + 10006060100611.

It is an arithmetic number, because the mean of its divisors is an integer number (10006060100611).

Almost surely, 2^{20012120201221} is an apocalyptic number.

It is an amenable number.

20012120201221 is a deficient number, since it is larger than the sum of its proper divisors (1).

20012120201221 is an equidigital number, since it uses as much as digits as its factorization.

20012120201221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 20012120201221 its reverse (12210202121002), we get a palindrome (32222322322223).

The spelling of 20012120201221 in words is "twenty trillion, twelve billion, one hundred twenty million, two hundred one thousand, two hundred twenty-one".