9447687016681 has 3 divisors (see below), whose sum is σ = 9447690090391. Its totient is φ = 9447683942972.

The previous prime is 9447687016667. The next prime is 9447687016697. The reversal of 9447687016681 is 1866107867449.

The square root of 9447687016681 is 3073709.

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., 4266327429081 + 5181359587600 = 2065509^2 + 2276260^2 .

It is not a de Polignac number, because 9447687016681 - 2⁴³ = 651593994473 is a prime.

It is a super-3 number, since 3×9447687016681³ (a number of 40 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9447687016601) 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, 1536855 + ... + 4610563.

Almost surely, 2^{9447687016681} is an apocalyptic number.

9447687016681 is the 3073709-th square number.

9447687016681 is the 1536855-th centered octagonal number.

It is an amenable number.

9447687016681 is a deficient number, since it is larger than the sum of its proper divisors (3073710).

9447687016681 is an frugal number, since it uses more digits than its factorization.

9447687016681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6147418 (or 3073709 counting only the distinct ones).

The product of its (nonzero) digits is 97542144, while the sum is 67.

The spelling of 9447687016681 in words is "nine trillion, four hundred forty-seven billion, six hundred eighty-seven million, sixteen thousand, six hundred eighty-one".