121501521521 has 2 divisors, whose sum is σ = 121501521522. Its totient is φ = 121501521520.

The previous prime is 121501521487. The next prime is 121501521523. The reversal of 121501521521 is 125125105121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 85462675600 + 36038845921 = 292340^2 + 189839^2 .

It is a cyclic number.

It is not a de Polignac number, because 121501521521 - 2²⁶ = 121434412657 is a prime.

Together with 121501521523, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (121501521523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60750760760 + 60750760761.

It is an arithmetic number, because the mean of its divisors is an integer number (60750760761).

Almost surely, 2^121501521521 is an apocalyptic number.

It is an amenable number.

121501521521 is a deficient number, since it is larger than the sum of its proper divisors (1).

121501521521 is an equidigital number, since it uses as much as digits as its factorization.

121501521521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1000, while the sum is 26.

Adding to 121501521521 its reverse (125125105121), we get a palindrome (246626626642).

The spelling of 121501521521 in words is "one hundred twenty-one billion, five hundred one million, five hundred twenty-one thousand, five hundred twenty-one".