12665476681 has 27 divisors (see below), whose sum is σ = 15094001223. Its totient is φ = 10614867120.

The previous prime is 12665476673. The next prime is 12665476699. The reversal of 12665476681 is 18667456621.

The square root of 12665476681 is 112541.

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

It can be written as a sum of positive squares in only one way, i.e., 1873591225 + 10791885456 = 43285^2 + 103884^2 .

It is not a de Polignac number, because 12665476681 - 2³ = 12665476673 is a prime.

It is a super-2 number, since 2×12665476681² (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 (12665476601) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 16092970 + ... + 16093756.

Almost surely, 2^12665476681 is an apocalyptic number.

12665476681 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

12665476681 is the 112541-st square number.

12665476681 is the 56271-st centered octagonal number.

It is an amenable number.

12665476681 is a deficient number, since it is larger than the sum of its proper divisors (2428524542).

12665476681 is an frugal number, since it uses more digits than its factorization.

12665476681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1622 (or 811 counting only the distinct ones).

The product of its digits is 2903040, while the sum is 52.

The spelling of 12665476681 in words is "twelve billion, six hundred sixty-five million, four hundred seventy-six thousand, six hundred eighty-one".