665677643 has 2 divisors, whose sum is σ = 665677644. Its totient is φ = 665677642.

The previous prime is 665677631. The next prime is 665677697. The reversal of 665677643 is 346776566.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 665677643 - 2⁴ = 665677627 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 665677591 and 665677600.

It is not a weakly prime, because it can be changed into another prime (665677603) 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 as a sum of consecutive naturals, namely, 332838821 + 332838822.

It is an arithmetic number, because the mean of its divisors is an integer number (332838822).

Almost surely, 2^665677643 is an apocalyptic number.

665677643 is a deficient number, since it is larger than the sum of its proper divisors (1).

665677643 is an equidigital number, since it uses as much as digits as its factorization.

665677643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3810240, while the sum is 50.

The square root of 665677643 is about 25800.7295051904. The cubic root of 665677643 is about 873.1482550558.

The spelling of 665677643 in words is "six hundred sixty-five million, six hundred seventy-seven thousand, six hundred forty-three".