666408905878011 has 4 divisors (see below), whose sum is σ = 888545207837352. Its totient is φ = 444272603918672.

The previous prime is 666408905877997. The next prime is 666408905878033. The reversal of 666408905878011 is 110878509804666.

666408905878011 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 666408905878011 - 2¹⁴ = 666408905861627 is a prime.

It is a super-2 number, since 2×666408905878011² (a number of 30 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (666408905878511) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111068150979666 + ... + 111068150979671.

It is an arithmetic number, because the mean of its divisors is an integer number (222136301959338).

Almost surely, 2^{666408905878011} is an apocalyptic number.

666408905878011 is a deficient number, since it is larger than the sum of its proper divisors (222136301959341).

666408905878011 is a wasteful number, since it uses less digits than its factorization.

666408905878011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222136301959340.

The product of its (nonzero) digits is 139345920, while the sum is 69.

The spelling of 666408905878011 in words is "six hundred sixty-six trillion, four hundred eight billion, nine hundred five million, eight hundred seventy-eight thousand, eleven".