20110101021221 has 2 divisors, whose sum is σ = 20110101021222. Its totient is φ = 20110101021220.

The previous prime is 20110101021193. The next prime is 20110101021247. The reversal of 20110101021221 is 12212010101102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13492030922500 + 6618070098721 = 3673150^2 + 2572561^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20110101021221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20110101021196 and 20110101021205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20110101021421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10055050510610 + 10055050510611.

It is an arithmetic number, because the mean of its divisors is an integer number (10055050510611).

Almost surely, 2^{20110101021221} is an apocalyptic number.

It is an amenable number.

20110101021221 is a deficient number, since it is larger than the sum of its proper divisors (1).

20110101021221 is an equidigital number, since it uses as much as digits as its factorization.

20110101021221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 20110101021221 its reverse (12212010101102), we get a palindrome (32322111122323).

The spelling of 20110101021221 in words is "twenty trillion, one hundred ten billion, one hundred one million, twenty-one thousand, two hundred twenty-one".