403666 has 4 divisors (see below), whose sum is σ = 605502. Its totient is φ = 201832.

The previous prime is 403661. The next prime is 403679. The reversal of 403666 is 666304.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 403225 + 441 = 635^2 + 21^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 403666.

It is not an unprimeable number, because it can be changed into a prime (403661) by changing a digit.

403666 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100915 + ... + 100918.

2⁴⁰³⁶⁶⁶ is an apocalyptic number.

403666 is a deficient number, since it is larger than the sum of its proper divisors (201836).

403666 is a wasteful number, since it uses less digits than its factorization.

403666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201835.

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

The square root of 403666 is about 635.3471492027. The cubic root of 403666 is about 73.9050401143.

The spelling of 403666 in words is "four hundred three thousand, six hundred sixty-six".