1666851666 has 16 divisors (see below), whose sum is σ = 3529803744. Its totient is φ = 522933824.

The previous prime is 1666851631. The next prime is 1666851673. The reversal of 1666851666 is 6661586661.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a Curzon 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, 8170740 + ... + 8170943.

It is an arithmetic number, because the mean of its divisors is an integer number (220612734).

Almost surely, 2^1666851666 is an apocalyptic number.

1666851666 is an abundant number, since it is smaller than the sum of its proper divisors (1862952078).

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

1666851666 is a wasteful number, since it uses less digits than its factorization.

1666851666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16341705.

The product of its digits is 1866240, while the sum is 51.

The square root of 1666851666 is about 40827.0947533620. The cubic root of 1666851666 is about 1185.6749680663.

The spelling of 1666851666 in words is "one billion, six hundred sixty-six million, eight hundred fifty-one thousand, six hundred sixty-six".