1666440345 has 8 divisors (see below), whose sum is σ = 2666304576. Its totient is φ = 888768176.

The previous prime is 1666440337. The next prime is 1666440359. The reversal of 1666440345 is 5430446661.

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 1666440345 - 2³ = 1666440337 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55547997 + ... + 55548026.

It is an arithmetic number, because the mean of its divisors is an integer number (333288072).

Almost surely, 2^1666440345 is an apocalyptic number.

1666440345 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1666440345 is a deficient number, since it is larger than the sum of its proper divisors (999864231).

1666440345 is a wasteful number, since it uses less digits than its factorization.

1666440345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111096031.

The product of its (nonzero) digits is 207360, while the sum is 39.

The square root of 1666440345 is about 40822.0570892747. The cubic root of 1666440345 is about 1185.5774322659.

The spelling of 1666440345 in words is "one billion, six hundred sixty-six million, four hundred forty thousand, three hundred forty-five".