121521065521 has 2 divisors, whose sum is σ = 121521065522. Its totient is φ = 121521065520.

The previous prime is 121521065483. The next prime is 121521065539. The reversal of 121521065521 is 125560125121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 68572754496 + 52948311025 = 261864^2 + 230105^2 .

It is a cyclic number.

It is not a de Polignac number, because 121521065521 - 2⁹ = 121521065009 is a prime.

It is not a weakly prime, because it can be changed into another prime (121521065581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60760532760 + 60760532761.

It is an arithmetic number, because the mean of its divisors is an integer number (60760532761).

Almost surely, 2^121521065521 is an apocalyptic number.

It is an amenable number.

121521065521 is a deficient number, since it is larger than the sum of its proper divisors (1).

121521065521 is an equidigital number, since it uses as much as digits as its factorization.

121521065521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6000, while the sum is 31.

The spelling of 121521065521 in words is "one hundred twenty-one billion, five hundred twenty-one million, sixty-five thousand, five hundred twenty-one".