666843941 has 4 divisors (see below), whose sum is σ = 667269984. Its totient is φ = 666417900.

The previous prime is 666843929. The next prime is 666843949. The reversal of 666843941 is 149348666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666843941 is a prime.

It is a super-2 number, since 2×666843941² = 889361683296822962, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666843949) 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, 210665 + ... + 213806.

It is an arithmetic number, because the mean of its divisors is an integer number (166817496).

Almost surely, 2^666843941 is an apocalyptic number.

It is an amenable number.

666843941 is a deficient number, since it is larger than the sum of its proper divisors (426043).

666843941 is a wasteful number, since it uses less digits than its factorization.

666843941 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 426042.

The product of its digits is 746496, while the sum is 47.

The square root of 666843941 is about 25823.3216492379. The cubic root of 666843941 is about 873.6578895712.

The spelling of 666843941 in words is "six hundred sixty-six million, eight hundred forty-three thousand, nine hundred forty-one".