6664578754665 has 16 divisors (see below), whose sum is σ = 11483581854528. Its totient is φ = 3281023386816.

The previous prime is 6664578754643. The next prime is 6664578754747. The reversal of 6664578754665 is 5664578754666.

It is not a de Polignac number, because 6664578754665 - 2¹³ = 6664578746473 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17088663279 + ... + 17088663668.

It is an arithmetic number, because the mean of its divisors is an integer number (717723865908).

Almost surely, 2^{6664578754665} is an apocalyptic number.

6664578754665 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

6664578754665 is a deficient number, since it is larger than the sum of its proper divisors (4819003099863).

6664578754665 is a wasteful number, since it uses less digits than its factorization.

6664578754665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34177326968.

The product of its digits is 6096384000, while the sum is 75.

Subtracting from 6664578754665 its reverse (5664578754666), we obtain a palindrome (999999999999).

The spelling of 6664578754665 in words is "six trillion, six hundred sixty-four billion, five hundred seventy-eight million, seven hundred fifty-four thousand, six hundred sixty-five".