221220121061 has 2 divisors, whose sum is σ = 221220121062. Its totient is φ = 221220121060.

The previous prime is 221220121037. The next prime is 221220121127. The reversal of 221220121061 is 160121022122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 220961104225 + 259016836 = 470065^2 + 16094^2 .

It is a cyclic number.

It is not a de Polignac number, because 221220121061 - 2¹⁸ = 221219858917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221220121261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110610060530 + 110610060531.

It is an arithmetic number, because the mean of its divisors is an integer number (110610060531).

Almost surely, 2^221220121061 is an apocalyptic number.

It is an amenable number.

221220121061 is a deficient number, since it is larger than the sum of its proper divisors (1).

221220121061 is an equidigital number, since it uses as much as digits as its factorization.

221220121061 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 20.

Adding to 221220121061 its reverse (160121022122), we get a palindrome (381341143183).

The spelling of 221220121061 in words is "two hundred twenty-one billion, two hundred twenty million, one hundred twenty-one thousand, sixty-one".