121220111221553 has 2 divisors, whose sum is σ = 121220111221554. Its totient is φ = 121220111221552.

The previous prime is 121220111221541. The next prime is 121220111221591. The reversal of 121220111221553 is 355122111022121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 74136525606049 + 47083585615504 = 8610257^2 + 6861748^2 .

It is a cyclic number.

It is not a de Polignac number, because 121220111221553 - 2³² = 121215816254257 is a prime.

It is not a weakly prime, because it can be changed into another prime (121220111221513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60610055610776 + 60610055610777.

It is an arithmetic number, because the mean of its divisors is an integer number (60610055610777).

Almost surely, 2^{121220111221553} is an apocalyptic number.

It is an amenable number.

121220111221553 is a deficient number, since it is larger than the sum of its proper divisors (1).

121220111221553 is an equidigital number, since it uses as much as digits as its factorization.

121220111221553 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2400, while the sum is 29.

Adding to 121220111221553 its reverse (355122111022121), we get a palindrome (476342222243674).

The spelling of 121220111221553 in words is "one hundred twenty-one trillion, two hundred twenty billion, one hundred eleven million, two hundred twenty-one thousand, five hundred fifty-three".