121220020861 has 2 divisors, whose sum is σ = 121220020862. Its totient is φ = 121220020860.

The previous prime is 121220020849. The next prime is 121220020913. The reversal of 121220020861 is 168020022121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 95945062500 + 25274958361 = 309750^2 + 158981^2 .

It is a cyclic number.

It is not a de Polignac number, because 121220020861 - 2¹¹ = 121220018813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121220020841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60610010430 + 60610010431.

It is an arithmetic number, because the mean of its divisors is an integer number (60610010431).

Almost surely, 2^121220020861 is an apocalyptic number.

It is an amenable number.

121220020861 is a deficient number, since it is larger than the sum of its proper divisors (1).

121220020861 is an equidigital number, since it uses as much as digits as its factorization.

121220020861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 768, while the sum is 25.

Adding to 121220020861 its reverse (168020022121), we get a palindrome (289240042982).

The spelling of 121220020861 in words is "one hundred twenty-one billion, two hundred twenty million, twenty thousand, eight hundred sixty-one".