12609309819681 has 39 divisors (see below), whose sum is σ = 18917836634593. Its totient is φ = 8404480780380.

The previous prime is 12609309819671. The next prime is 12609309819713. The reversal of 12609309819681 is 18691890390621.

The square root of 12609309819681 is 3550959.

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

12609309819681 is a `hidden beast` number, since 1 + 2 + 60 + 9 + 309 + 8 + 196 + 81 = 666.

It is not a de Polignac number, because 12609309819681 - 2¹¹ = 12609309817633 is a prime.

It is a super-2 number, since 2×12609309819681² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12609309819671) by changing a digit.

It is a polite number, since it can be written in 38 ways as a sum of consecutive naturals, for example, 2588646676 + ... + 2588651546.

Almost surely, 2^{12609309819681} is an apocalyptic number.

12609309819681 is the 3550959-th square number.

12609309819681 is the 1775480-th centered octagonal number.

It is an amenable number.

12609309819681 is a deficient number, since it is larger than the sum of its proper divisors (6308526814912).

12609309819681 is an frugal number, since it uses more digits than its factorization.

12609309819681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9778 (or 4874 counting only the distinct ones).

The product of its (nonzero) digits is 10077696, while the sum is 63.

The spelling of 12609309819681 in words is "twelve trillion, six hundred nine billion, three hundred nine million, eight hundred nineteen thousand, six hundred eighty-one".