221201323121 has 2 divisors, whose sum is σ = 221201323122. Its totient is φ = 221201323120.

The previous prime is 221201323097. The next prime is 221201323141. The reversal of 221201323121 is 121323102122.

It is an a-pointer prime, because the next prime (221201323141) can be obtained adding 221201323121 to its sum of digits (20).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 183034230625 + 38167092496 = 427825^2 + 195364^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221201323121 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221201323093 and 221201323102.

It is not a weakly prime, because it can be changed into another prime (221201323141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110600661560 + 110600661561.

It is an arithmetic number, because the mean of its divisors is an integer number (110600661561).

Almost surely, 2^221201323121 is an apocalyptic number.

It is an amenable number.

221201323121 is a deficient number, since it is larger than the sum of its proper divisors (1).

221201323121 is an equidigital number, since it uses as much as digits as its factorization.

221201323121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 221201323121 its reverse (121323102122), we get a palindrome (342524425243).

The spelling of 221201323121 in words is "two hundred twenty-one billion, two hundred one million, three hundred twenty-three thousand, one hundred twenty-one".