102111201221 has 2 divisors, whose sum is σ = 102111201222. Its totient is φ = 102111201220.

The previous prime is 102111201211. The next prime is 102111201251. The reversal of 102111201221 is 122102111201.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 95675150596 + 6436050625 = 309314^2 + 80225^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-102111201221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 102111201196 and 102111201205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (102111201211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51055600610 + 51055600611.

It is an arithmetic number, because the mean of its divisors is an integer number (51055600611).

Almost surely, 2^102111201221 is an apocalyptic number.

It is an amenable number.

102111201221 is a deficient number, since it is larger than the sum of its proper divisors (1).

102111201221 is an equidigital number, since it uses as much as digits as its factorization.

102111201221 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 14.

Adding to 102111201221 its reverse (122102111201), we get a palindrome (224213312422).

The spelling of 102111201221 in words is "one hundred two billion, one hundred eleven million, two hundred one thousand, two hundred twenty-one".