11709620521 has 3 divisors (see below), whose sum is σ = 11709728733. Its totient is φ = 11709512310.

The previous prime is 11709620509. The next prime is 11709620539. The reversal of 11709620521 is 12502690711.

The square root of 11709620521 is 108211.

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

11709620521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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: 12502690711 = 7 ⋅1786098673.

It is not a de Polignac number, because 11709620521 - 2²⁷ = 11575402793 is a prime.

It is a super-2 number, since 2×11709620521² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11709620501) 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 in 2 ways as a sum of consecutive naturals, for example, 54106 + ... + 162316.

It is an arithmetic number, because the mean of its divisors is an integer number (3903242911).

Almost surely, 2^11709620521 is an apocalyptic number.

11709620521 is the 108211-st square number.

11709620521 is the 54106-th centered octagonal number.

It is an amenable number.

11709620521 is a deficient number, since it is larger than the sum of its proper divisors (108212).

11709620521 is an frugal number, since it uses more digits than its factorization.

11709620521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216422 (or 108211 counting only the distinct ones).

The product of its (nonzero) digits is 7560, while the sum is 34.

The spelling of 11709620521 in words is "eleven billion, seven hundred nine million, six hundred twenty thousand, five hundred twenty-one".