12665510661 has 16 divisors (see below), whose sum is σ = 16929338048. Its totient is φ = 8422704000.

The previous prime is 12665510659. The next prime is 12665510699. The reversal of 12665510661 is 16601556621.

It is not a de Polignac number, because 12665510661 - 2¹ = 12665510659 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12665510621) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3147831 + ... + 3151851.

It is an arithmetic number, because the mean of its divisors is an integer number (1058083628).

Almost surely, 2^12665510661 is an apocalyptic number.

It is an amenable number.

12665510661 is a deficient number, since it is larger than the sum of its proper divisors (4263827387).

12665510661 is a wasteful number, since it uses less digits than its factorization.

12665510661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6372.

The product of its (nonzero) digits is 64800, while the sum is 39.

The spelling of 12665510661 in words is "twelve billion, six hundred sixty-five million, five hundred ten thousand, six hundred sixty-one".