664998 has 16 divisors (see below), whose sum is σ = 1341360. Its totient is φ = 219776.

The previous prime is 664997. The next prime is 665011. The reversal of 664998 is 899466.

It is a plaindrome in base 14.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 664998.

It is not an unprimeable number, because it can be changed into a prime (664997) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 418 + ... + 1226.

It is an arithmetic number, because the mean of its divisors is an integer number (83835).

2⁶⁶⁴⁹⁹⁸ is an apocalyptic number.

664998 is an abundant number, since it is smaller than the sum of its proper divisors (676362).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

664998 is a wasteful number, since it uses less digits than its factorization.

664998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 951.

The product of its digits is 93312, while the sum is 42.

The square root of 664998 is about 815.4740952354. The cubic root of 664998 is about 87.2850998478.

The spelling of 664998 in words is "six hundred sixty-four thousand, nine hundred ninety-eight".