1666357317 has 12 divisors (see below), whose sum is σ = 2458173120. Its totient is φ = 1087268328.

The previous prime is 1666357309. The next prime is 1666357321. The reversal of 1666357317 is 7137536661.

It is not a de Polignac number, because 1666357317 - 2³ = 1666357309 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666357367) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1969267 + ... + 1970112.

It is an arithmetic number, because the mean of its divisors is an integer number (204847760).

Almost surely, 2^1666357317 is an apocalyptic number.

It is an amenable number.

1666357317 is a deficient number, since it is larger than the sum of its proper divisors (791815803).

1666357317 is a wasteful number, since it uses less digits than its factorization.

1666357317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3939432 (or 3939429 counting only the distinct ones).

The product of its digits is 476280, while the sum is 45.

The square root of 1666357317 is about 40821.0401263858. The cubic root of 1666357317 is about 1185.5577420405.

The spelling of 1666357317 in words is "one billion, six hundred sixty-six million, three hundred fifty-seven thousand, three hundred seventeen".