663406 has 8 divisors (see below), whose sum is σ = 1006560. Its totient is φ = 327888.

The previous prime is 663371. The next prime is 663407. The reversal of 663406 is 604366.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663407) 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, 1686 + ... + 2041.

It is an arithmetic number, because the mean of its divisors is an integer number (125820).

2⁶⁶³⁴⁰⁶ is an apocalyptic number.

663406 is a deficient number, since it is larger than the sum of its proper divisors (343154).

663406 is a wasteful number, since it uses less digits than its factorization.

663406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3818.

The product of its (nonzero) digits is 2592, while the sum is 25.

The square root of 663406 is about 814.4973910333. The cubic root of 663406 is about 87.2153909090.

The spelling of 663406 in words is "six hundred sixty-three thousand, four hundred six".