1666081200 has 240 divisors, whose sum is σ = 6132194816. Its totient is φ = 378777600.

The previous prime is 1666081163. The next prime is 1666081229. The reversal of 1666081200 is 21806661.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2023989 + ... + 2024811.

Almost surely, 2^1666081200 is an apocalyptic number.

1666081200 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 1666081200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3066097408).

1666081200 is an abundant number, since it is smaller than the sum of its proper divisors (4466113616).

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

1666081200 is a wasteful number, since it uses less digits than its factorization.

1666081200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1092 (or 1081 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 1666081200 is about 40817.6579435910. The cubic root of 1666081200 is about 1185.4922557397.

Adding to 1666081200 its reverse (21806661), we get a palindrome (1687887861).

The spelling of 1666081200 in words is "one billion, six hundred sixty-six million, eighty-one thousand, two hundred".