1666843357 has 16 divisors (see below), whose sum is σ = 1751777280. Its totient is φ = 1584601200.

The previous prime is 1666843351. The next prime is 1666843403. The reversal of 1666843357 is 7533486661.

It is a cyclic number.

It is not a de Polignac number, because 1666843357 - 2³ = 1666843349 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1666843357.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666843351) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 237732 + ... + 244642.

It is an arithmetic number, because the mean of its divisors is an integer number (109486080).

Almost surely, 2^1666843357 is an apocalyptic number.

It is an amenable number.

1666843357 is a deficient number, since it is larger than the sum of its proper divisors (84933923).

1666843357 is an equidigital number, since it uses as much as digits as its factorization.

1666843357 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7104.

The product of its digits is 2177280, while the sum is 49.

The square root of 1666843357 is about 40826.9929948313. The cubic root of 1666843357 is about 1185.6729979271.

It can be divided in two parts, 16668 and 43357, that added together give a square (60025 = 245²).

The spelling of 1666843357 in words is "one billion, six hundred sixty-six million, eight hundred forty-three thousand, three hundred fifty-seven".