665403 has 8 divisors (see below), whose sum is σ = 891408. Its totient is φ = 441504.

The previous prime is 665387. The next prime is 665419. The reversal of 665403 is 304566.

It is an interprime number because it is at equal distance from previous prime (665387) and next prime (665419).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 665403 - 2⁴ = 665387 is a prime.

It is a super-2 number, since 2×665403² = 885522304818, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (665303) 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 in 7 ways as a sum of consecutive naturals, for example, 501 + ... + 1257.

It is an arithmetic number, because the mean of its divisors is an integer number (111426).

2⁶⁶⁵⁴⁰³ is an apocalyptic number.

665403 is a deficient number, since it is larger than the sum of its proper divisors (226005).

665403 is a wasteful number, since it uses less digits than its factorization.

665403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1053.

The product of its (nonzero) digits is 2160, while the sum is 24.

The square root of 665403 is about 815.7223792443. The cubic root of 665403 is about 87.3028158367.

Adding to 665403 its reverse (304566), we get a palindrome (969969).

The spelling of 665403 in words is "six hundred sixty-five thousand, four hundred three".