121220111221541 has 2 divisors, whose sum is σ = 121220111221542. Its totient is φ = 121220111221540.

The previous prime is 121220111221513. The next prime is 121220111221553. The reversal of 121220111221541 is 145122111022121.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69392998420516 + 51827112801025 = 8330246^2 + 7199105^2 .

It is a cyclic number.

It is not a de Polignac number, because 121220111221541 - 2²⁶ = 121220044112677 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 121220111221541.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121220111221591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60610055610770 + 60610055610771.

It is an arithmetic number, because the mean of its divisors is an integer number (60610055610771).

Almost surely, 2^{121220111221541} is an apocalyptic number.

It is an amenable number.

121220111221541 is a deficient number, since it is larger than the sum of its proper divisors (1).

121220111221541 is an equidigital number, since it uses as much as digits as its factorization.

121220111221541 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 640, while the sum is 26.

Adding to 121220111221541 its reverse (145122111022121), we get a palindrome (266342222243662).

The spelling of 121220111221541 in words is "one hundred twenty-one trillion, two hundred twenty billion, one hundred eleven million, two hundred twenty-one thousand, five hundred forty-one".