12666780037665 has 160 divisors (see below), whose sum is σ = 25934508585216. Its totient is φ = 5867037411840.

The previous prime is 12666780037531. The next prime is 12666780037729. The reversal of 12666780037665 is 56673008766621.

It is not a de Polignac number, because 12666780037665 - 2⁸ = 12666780037409 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 6529402 + ... + 8244188.

Almost surely, 2^{12666780037665} is an apocalyptic number.

12666780037665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

12666780037665 is an abundant number, since it is smaller than the sum of its proper divisors (13267728547551).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12666780037665 is a wasteful number, since it uses less digits than its factorization.

12666780037665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1714901 (or 1714892 counting only the distinct ones).

The product of its (nonzero) digits is 91445760, while the sum is 63.

The spelling of 12666780037665 in words is "twelve trillion, six hundred sixty-six billion, seven hundred eighty million, thirty-seven thousand, six hundred sixty-five".