1666220200 has 48 divisors (see below), whose sum is σ = 4077864000. Its totient is φ = 631408320.

The previous prime is 1666220189. The next prime is 1666220207. The reversal of 1666220200 is 20226661.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (1666220207) 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, 215440 + ... + 223039.

It is an arithmetic number, because the mean of its divisors is an integer number (84955500).

Almost surely, 2^1666220200 is an apocalyptic number.

1666220200 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1666220200 is an abundant number, since it is smaller than the sum of its proper divisors (2411643800).

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

1666220200 is a wasteful number, since it uses less digits than its factorization.

1666220200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 438514 (or 438505 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 1666220200 is about 40819.3606025376. The cubic root of 1666220200 is about 1185.5252230887.

Adding to 1666220200 its reverse (20226661), we get a palindrome (1686446861).

The spelling of 1666220200 in words is "one billion, six hundred sixty-six million, two hundred twenty thousand, two hundred".