663409 has 2 divisors, whose sum is σ = 663410. Its totient is φ = 663408.

The previous prime is 663407. The next prime is 663437. The reversal of 663409 is 904366.

It is an a-pointer prime, because the next prime (663437) can be obtained adding 663409 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 640000 + 23409 = 800^2 + 153^2 .

It is a cyclic number.

It is not a de Polignac number, because 663409 - 2¹ = 663407 is a prime.

It is a super-2 number, since 2×663409² = 880223002562, which contains 22 as substring.

Together with 663407, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (663407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 331704 + 331705.

It is an arithmetic number, because the mean of its divisors is an integer number (331705).

2⁶⁶³⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

663409 is a deficient number, since it is larger than the sum of its proper divisors (1).

663409 is an equidigital number, since it uses as much as digits as its factorization.

663409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 28.

The square root of 663409 is about 814.4992326577. The cubic root of 663409 is about 87.2155223749.

The spelling of 663409 in words is "six hundred sixty-three thousand, four hundred nine".