665567843 has 4 divisors (see below), whose sum is σ = 671674080. Its totient is φ = 659461608.

The previous prime is 665567839. The next prime is 665567857. The reversal of 665567843 is 348765566.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 665567843 - 2² = 665567839 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 665567791 and 665567800.

It is not an unprimeable number, because it can be changed into a prime (665567863) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3052955 + ... + 3053172.

It is an arithmetic number, because the mean of its divisors is an integer number (167918520).

Almost surely, 2^665567843 is an apocalyptic number.

665567843 is a deficient number, since it is larger than the sum of its proper divisors (6106237).

665567843 is a wasteful number, since it uses less digits than its factorization.

665567843 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6106236.

The product of its digits is 3628800, while the sum is 50.

The square root of 665567843 is about 25798.6015706278. The cubic root of 665567843 is about 873.1002453567.

The spelling of 665567843 in words is "six hundred sixty-five million, five hundred sixty-seven thousand, eight hundred forty-three".