221240242121 has 2 divisors, whose sum is σ = 221240242122. Its totient is φ = 221240242120.

The previous prime is 221240242117. The next prime is 221240242127. The reversal of 221240242121 is 121242042122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 153346644025 + 67893598096 = 391595^2 + 260564^2 .

It is a cyclic number.

It is not a de Polignac number, because 221240242121 - 2² = 221240242117 is a prime.

It is not a weakly prime, because it can be changed into another prime (221240242127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110620121060 + 110620121061.

It is an arithmetic number, because the mean of its divisors is an integer number (110620121061).

Almost surely, 2^221240242121 is an apocalyptic number.

It is an amenable number.

221240242121 is a deficient number, since it is larger than the sum of its proper divisors (1).

221240242121 is an equidigital number, since it uses as much as digits as its factorization.

221240242121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1024, while the sum is 23.

Adding to 221240242121 its reverse (121242042122), we get a palindrome (342482284243).

The spelling of 221240242121 in words is "two hundred twenty-one billion, two hundred forty million, two hundred forty-two thousand, one hundred twenty-one".