1666843351 has 2 divisors, whose sum is σ = 1666843352. Its totient is φ = 1666843350.

The previous prime is 1666843349. The next prime is 1666843403. The reversal of 1666843351 is 1533486661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1666843351 - 2¹ = 1666843349 is a prime.

Together with 1666843349, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 1666843298 and 1666843307.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1666843331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833421675 + 833421676.

It is an arithmetic number, because the mean of its divisors is an integer number (833421676).

Almost surely, 2^1666843351 is an apocalyptic number.

1666843351 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666843351 is an equidigital number, since it uses as much as digits as its factorization.

1666843351 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 311040, while the sum is 43.

The square root of 1666843351 is about 40826.9929213505. The cubic root of 1666843351 is about 1185.6729965044.

The spelling of 1666843351 in words is "one billion, six hundred sixty-six million, eight hundred forty-three thousand, three hundred fifty-one".