120208517521 has 3 divisors (see below), whose sum is σ = 120208864233. Its totient is φ = 120208170810.

The previous prime is 120208517483. The next prime is 120208517549. The reversal of 120208517521 is 125715802021.

The square root of 120208517521 is 346711.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 125715802021 = 19 ⋅6616621159.

It is not a de Polignac number, because 120208517521 - 2¹³ = 120208509329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (120208517591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 173356 + ... + 520066.

It is an arithmetic number, because the mean of its divisors is an integer number (40069621411).

Almost surely, 2^120208517521 is an apocalyptic number.

120208517521 is the 346711-st square number.

120208517521 is the 173356-th centered octagonal number.

It is an amenable number.

120208517521 is a deficient number, since it is larger than the sum of its proper divisors (346712).

120208517521 is an frugal number, since it uses more digits than its factorization.

120208517521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 693422 (or 346711 counting only the distinct ones).

The product of its (nonzero) digits is 11200, while the sum is 34.

The spelling of 120208517521 in words is "one hundred twenty billion, two hundred eight million, five hundred seventeen thousand, five hundred twenty-one".