20010020001221 has 2 divisors, whose sum is σ = 20010020001222. Its totient is φ = 20010020001220.

The previous prime is 20010020001149. The next prime is 20010020001277. The reversal of 20010020001221 is 12210002001002.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16099755002500 + 3910264998721 = 4012450^2 + 1977439^2 .

It is a cyclic number.

It is not a de Polignac number, because 20010020001221 - 2³⁴ = 19992840132037 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20010020007221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10005010000610 + 10005010000611.

It is an arithmetic number, because the mean of its divisors is an integer number (10005010000611).

Almost surely, 2^{20010020001221} is an apocalyptic number.

It is an amenable number.

20010020001221 is a deficient number, since it is larger than the sum of its proper divisors (1).

20010020001221 is an equidigital number, since it uses as much as digits as its factorization.

20010020001221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 20010020001221 its reverse (12210002001002), we get a palindrome (32220022002223).

The spelling of 20010020001221 in words is "twenty trillion, ten billion, twenty million, one thousand, two hundred twenty-one".