1666868736 has 80 divisors (see below), whose sum is σ = 4782287664. Its totient is φ = 512876544.

The previous prime is 1666868713. The next prime is 1666868743. The reversal of 1666868736 is 6378686661.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21771 + ... + 61706.

Almost surely, 2^1666868736 is an apocalyptic number.

1666868736 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1666868736 is an abundant number, since it is smaller than the sum of its proper divisors (3115418928).

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

1666868736 is an equidigital number, since it uses as much as digits as its factorization.

1666868736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83511 (or 83495 counting only the distinct ones).

The product of its digits is 10450944, while the sum is 57.

The square root of 1666868736 is about 40827.3038051743. The cubic root of 1666868736 is about 1185.6790154976.

The spelling of 1666868736 in words is "one billion, six hundred sixty-six million, eight hundred sixty-eight thousand, seven hundred thirty-six".