1666843331 has 2 divisors, whose sum is σ = 1666843332. Its totient is φ = 1666843330.

The previous prime is 1666843307. The next prime is 1666843337. The reversal of 1666843331 is 1333486661.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1666843331 is a prime.

It is a super-2 number, since 2×1666843331² = 5556733380198351122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1666843337) 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 as a sum of consecutive naturals, namely, 833421665 + 833421666.

It is an arithmetic number, because the mean of its divisors is an integer number (833421666).

Almost surely, 2^1666843331 is an apocalyptic number.

1666843331 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666843331 is an equidigital number, since it uses as much as digits as its factorization.

1666843331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 186624, while the sum is 41.

The square root of 1666843331 is about 40826.9926764145. The cubic root of 1666843331 is about 1185.6729917622.

The spelling of 1666843331 in words is "one billion, six hundred sixty-six million, eight hundred forty-three thousand, three hundred thirty-one".