121355241521 has 2 divisors, whose sum is σ = 121355241522. Its totient is φ = 121355241520.

The previous prime is 121355241509. The next prime is 121355241569. The reversal of 121355241521 is 125142553121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 120470773921 + 884467600 = 347089^2 + 29740^2 .

It is an emirp because it is prime and its reverse (125142553121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121355241521 - 2¹⁸ = 121354979377 is a prime.

It is not a weakly prime, because it can be changed into another prime (121355541521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60677620760 + 60677620761.

It is an arithmetic number, because the mean of its divisors is an integer number (60677620761).

Almost surely, 2^121355241521 is an apocalyptic number.

It is an amenable number.

121355241521 is a deficient number, since it is larger than the sum of its proper divisors (1).

121355241521 is an equidigital number, since it uses as much as digits as its factorization.

121355241521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12000, while the sum is 32.

Adding to 121355241521 its reverse (125142553121), we get a palindrome (246497794642).

The spelling of 121355241521 in words is "one hundred twenty-one billion, three hundred fifty-five million, two hundred forty-one thousand, five hundred twenty-one".