398666 has 8 divisors (see below), whose sum is σ = 609444. Its totient is φ = 195520.

The previous prime is 398627. The next prime is 398669. The reversal of 398666 is 666893.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 395641 + 3025 = 629^2 + 55^2 .

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

398666 is a modest number, since divided by 666 gives 398 as remainder.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (398669) 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, 1775 + ... + 1986.

2³⁹⁸⁶⁶⁶ is an apocalyptic number.

398666 is a deficient number, since it is larger than the sum of its proper divisors (210778).

398666 is a wasteful number, since it uses less digits than its factorization.

398666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3816.

The product of its digits is 46656, while the sum is 38.

The square root of 398666 is about 631.4000316756. The cubic root of 398666 is about 73.5986304487.

The spelling of 398666 in words is "three hundred ninety-eight thousand, six hundred sixty-six".