1866666680 has 64 divisors (see below), whose sum is σ = 4311014400. Its totient is φ = 727189120.

The previous prime is 1866666677. The next prime is 1866666689. The reversal of 1866666680 is 866666681.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1866666689) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 231761 + ... + 239679.

It is an arithmetic number, because the mean of its divisors is an integer number (67359600).

Almost surely, 2^1866666680 is an apocalyptic number.

1866666680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1866666680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2155507200).

1866666680 is an abundant number, since it is smaller than the sum of its proper divisors (2444347720).

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

1866666680 is a wasteful number, since it uses less digits than its factorization.

1866666680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8084 (or 8080 counting only the distinct ones).

The product of its (nonzero) digits is 2985984, while the sum is 53.

The square root of 1866666680 is about 43204.9381436891. The cubic root of 1866666680 is about 1231.2765032302.

Subtracting from 1866666680 its reverse (866666681), we obtain a palindrome (999999999).

The spelling of 1866666680 in words is "one billion, eight hundred sixty-six million, six hundred sixty-six thousand, six hundred eighty".