1665051666 has 16 divisors (see below), whose sum is σ = 3331166688. Its totient is φ = 554840000.

The previous prime is 1665051659. The next prime is 1665051667. The reversal of 1665051666 is 6661505661.

It is not an unprimeable number, because it can be changed into a prime (1665051667) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23175 + ... + 62186.

It is an arithmetic number, because the mean of its divisors is an integer number (208197918).

Almost surely, 2^1665051666 is an apocalyptic number.

1665051666 is an abundant number, since it is smaller than the sum of its proper divisors (1666115022).

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

1665051666 is a wasteful number, since it uses less digits than its factorization.

1665051666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88617.

The product of its (nonzero) digits is 194400, while the sum is 42.

The square root of 1665051666 is about 40805.0446146062. The cubic root of 1665051666 is about 1185.2480187304.

The spelling of 1665051666 in words is "one billion, six hundred sixty-five million, fifty-one thousand, six hundred sixty-six".