10101212221 has 2 divisors, whose sum is σ = 10101212222. Its totient is φ = 10101212220.

The previous prime is 10101212161. The next prime is 10101212257. The reversal of 10101212221 is 12221210101.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10077348996 + 23863225 = 100386^2 + 4885^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-10101212221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (10101212621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5050606110 + 5050606111.

It is an arithmetic number, because the mean of its divisors is an integer number (5050606111).

Almost surely, 2^10101212221 is an apocalyptic number.

It is an amenable number.

10101212221 is a deficient number, since it is larger than the sum of its proper divisors (1).

10101212221 is an equidigital number, since it uses as much as digits as its factorization.

10101212221 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 13.

Adding to 10101212221 its reverse (12221210101), we get a palindrome (22322422322).

The spelling of 10101212221 in words is "ten billion, one hundred one million, two hundred twelve thousand, two hundred twenty-one".