666843441 has 16 divisors (see below), whose sum is σ = 992513280. Its totient is φ = 394747920.

The previous prime is 666843427. The next prime is 666843491. The reversal of 666843441 is 144348666.

It is a happy number.

It is not a de Polignac number, because 666843441 - 2¹¹ = 666841393 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 666843393 and 666843402.

It is not an unprimeable number, because it can be changed into a prime (666843421) 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, 233551 + ... + 236388.

It is an arithmetic number, because the mean of its divisors is an integer number (62032080).

Almost surely, 2^666843441 is an apocalyptic number.

It is an amenable number.

666843441 is a deficient number, since it is larger than the sum of its proper divisors (325669839).

666843441 is a wasteful number, since it uses less digits than its factorization.

666843441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 469996.

The product of its digits is 331776, while the sum is 42.

The square root of 666843441 is about 25823.3119680648. The cubic root of 666843441 is about 873.6576712148.

It can be divided in two parts, 66684 and 3441, that added together give a triangular number (70125 = T₃₇₄).

The spelling of 666843441 in words is "six hundred sixty-six million, eight hundred forty-three thousand, four hundred forty-one".