660689443 has 2 divisors, whose sum is σ = 660689444. Its totient is φ = 660689442.

The previous prime is 660689431. The next prime is 660689531. The reversal of 660689443 is 344986066.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-660689443 is a prime.

It is a super-4 number, since 4×660689443⁴ (a number of 36 digits) contains 4444 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 660689393 and 660689402.

It is not a weakly prime, because it can be changed into another prime (660689423) 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, 330344721 + 330344722.

It is an arithmetic number, because the mean of its divisors is an integer number (330344722).

Almost surely, 2^660689443 is an apocalyptic number.

660689443 is a deficient number, since it is larger than the sum of its proper divisors (1).

660689443 is an equidigital number, since it uses as much as digits as its factorization.

660689443 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 746496, while the sum is 46.

The square root of 660689443 is about 25703.8799211325. The cubic root of 660689443 is about 870.9618300764.

The spelling of 660689443 in words is "six hundred sixty million, six hundred eighty-nine thousand, four hundred forty-three".