666598 has 4 divisors (see below), whose sum is σ = 999900. Its totient is φ = 333298.

The previous prime is 666559. The next prime is 666599. The reversal of 666598 is 895666.

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

It is a self number, because there is not a number n which added to its sum of digits gives 666598.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666599) 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 as a sum of consecutive naturals, namely, 166648 + ... + 166651.

It is an arithmetic number, because the mean of its divisors is an integer number (249975).

2⁶⁶⁶⁵⁹⁸ is an apocalyptic number.

666598 is a deficient number, since it is larger than the sum of its proper divisors (333302).

666598 is a wasteful number, since it uses less digits than its factorization.

666598 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333301.

The product of its digits is 77760, while the sum is 40.

The square root of 666598 is about 816.4545302710. The cubic root of 666598 is about 87.3550470777.

The spelling of 666598 in words is "six hundred sixty-six thousand, five hundred ninety-eight".