1666173359 has 4 divisors (see below), whose sum is σ = 1701623904. Its totient is φ = 1630722816.

The previous prime is 1666173347. The next prime is 1666173367. The reversal of 1666173359 is 9533716661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9533716661 = 7 ⋅1361959523.

It is a cyclic number.

It is not a de Polignac number, because 1666173359 - 2⁴ = 1666173343 is a prime.

It is a super-2 number, since 2×1666173359² = 5552267324482685762, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (47), and also a Moran number because the ratio is a prime number: 35450497 = 1666173359 / (1 + 6 + 6 + 6 + 1 + 7 + 3 + 3 + 5 + 9).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666173329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17725202 + ... + 17725295.

It is an arithmetic number, because the mean of its divisors is an integer number (425405976).

Almost surely, 2^1666173359 is an apocalyptic number.

1666173359 is a deficient number, since it is larger than the sum of its proper divisors (35450545).

1666173359 is an equidigital number, since it uses as much as digits as its factorization.

1666173359 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35450544.

The product of its digits is 612360, while the sum is 47.

The square root of 1666173359 is about 40818.7868389054. The cubic root of 1666173359 is about 1185.5141137713.

The spelling of 1666173359 in words is "one billion, six hundred sixty-six million, one hundred seventy-three thousand, three hundred fifty-nine".