11927967708721 has 3 divisors (see below), whose sum is σ = 11927971162411. Its totient is φ = 11927964255032.

The previous prime is 11927967708691. The next prime is 11927967708733. The reversal of 11927967708721 is 12780776972911.

It is a happy number.

The square root of 11927967708721 is 3453689.

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.

It can be written as a sum of positive squares in only one way, i.e., 892815222321 + 11035152486400 = 944889^2 + 3321920^2 .

It is not a de Polignac number, because 11927967708721 - 2¹⁷ = 11927967577649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11927967708521) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 1726845 + ... + 5180533.

Almost surely, 2^{11927967708721} is an apocalyptic number.

11927967708721 is the 3453689-th square number.

11927967708721 is the 1726845-th centered octagonal number.

It is an amenable number.

11927967708721 is a deficient number, since it is larger than the sum of its proper divisors (3453690).

11927967708721 is an frugal number, since it uses more digits than its factorization.

11927967708721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6907378 (or 3453689 counting only the distinct ones).

The product of its (nonzero) digits is 37340352, while the sum is 67.

The spelling of 11927967708721 in words is "eleven trillion, nine hundred twenty-seven billion, nine hundred sixty-seven million, seven hundred eight thousand, seven hundred twenty-one".