1666666887 has 8 divisors (see below), whose sum is σ = 2282282736. Its totient is φ = 1081081152.

The previous prime is 1666666873. The next prime is 1666666913. The reversal of 1666666887 is 7886666661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1666666887 - 2⁶ = 1666666823 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1666666887.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666666817) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7507398 + ... + 7507619.

It is an arithmetic number, because the mean of its divisors is an integer number (285285342).

Almost surely, 2^1666666887 is an apocalyptic number.

1666666887 is a deficient number, since it is larger than the sum of its proper divisors (615615849).

1666666887 is a wasteful number, since it uses less digits than its factorization.

1666666887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15015057.

The product of its digits is 20901888, while the sum is 60.

The square root of 1666666887 is about 40824.8317449074. The cubic root of 1666666887 is about 1185.6311537435.

The spelling of 1666666887 in words is "one billion, six hundred sixty-six million, six hundred sixty-six thousand, eight hundred eighty-seven".