1666803989 has 8 divisors (see below), whose sum is σ = 1684143552. Its totient is φ = 1649486880.

The previous prime is 1666803979. The next prime is 1666803991. The reversal of 1666803989 is 9893086661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1666803989 - 2²⁴ = 1650026773 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666803979) 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, 172562 + ... + 181964.

It is an arithmetic number, because the mean of its divisors is an integer number (210517944).

Almost surely, 2^1666803989 is an apocalyptic number.

It is an amenable number.

1666803989 is a deficient number, since it is larger than the sum of its proper divisors (17339563).

1666803989 is a wasteful number, since it uses less digits than its factorization.

1666803989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11227.

The product of its (nonzero) digits is 3359232, while the sum is 56.

The square root of 1666803989 is about 40826.5108599792. The cubic root of 1666803989 is about 1185.6636633283.

The spelling of 1666803989 in words is "one billion, six hundred sixty-six million, eight hundred three thousand, nine hundred eighty-nine".