1666666872 has 48 divisors (see below), whose sum is σ = 4861114440. Its totient is φ = 512820288.

The previous prime is 1666666867. The next prime is 1666666873. The reversal of 1666666872 is 2786666661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666666873) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 889378 + ... + 891249.

Almost surely, 2^1666666872 is an apocalyptic number.

1666666872 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1666666872 is an abundant number, since it is smaller than the sum of its proper divisors (3194447568).

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

1666666872 is a wasteful number, since it uses less digits than its factorization.

1666666872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1780652 (or 1780645 counting only the distinct ones).

The product of its digits is 5225472, while the sum is 54.

The square root of 1666666872 is about 40824.8315611957. The cubic root of 1666666872 is about 1185.6311501866.

It can be divided in two parts, 16666 and 66872, that added together give a palindrome (83538).

The spelling of 1666666872 in words is "one billion, six hundred sixty-six million, six hundred sixty-six thousand, eight hundred seventy-two".