667385518278555 has 80 divisors (see below), whose sum is σ = 1248448652447040. Its totient is φ = 340440677609472.

The previous prime is 667385518278527. The next prime is 667385518278613. The reversal of 667385518278555 is 555872815583766.

667385518278555 is a `hidden beast` number, since 6 + 6 + 7 + 3 + 8 + 5 + 51 + 8 + 2 + 7 + 8 + 555 = 666.

It is not a de Polignac number, because 667385518278555 - 2⁸ = 667385518278299 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 138028351 + ... + 142781639.

It is an arithmetic number, because the mean of its divisors is an integer number (15605608155588).

Almost surely, 2^{667385518278555} is an apocalyptic number.

667385518278555 is a deficient number, since it is larger than the sum of its proper divisors (581063134168485).

667385518278555 is a wasteful number, since it uses less digits than its factorization.

667385518278555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4768402 (or 4768393 counting only the distinct ones).

The product of its digits is 16934400000, while the sum is 81.

The spelling of 667385518278555 in words is "six hundred sixty-seven trillion, three hundred eighty-five billion, five hundred eighteen million, two hundred seventy-eight thousand, five hundred fifty-five".