666698 has 4 divisors (see below), whose sum is σ = 1000050. Its totient is φ = 333348.

The previous prime is 666697. The next prime is 666707. The reversal of 666698 is 896666.

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., 597529 + 69169 = 773^2 + 263^2 .

It is not an unprimeable number, because it can be changed into a prime (666697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166673 + ... + 166676.

2⁶⁶⁶⁶⁹⁸ is an apocalyptic number.

666698 is a deficient number, since it is larger than the sum of its proper divisors (333352).

666698 is a wasteful number, since it uses less digits than its factorization.

666698 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333351.

The product of its digits is 93312, while the sum is 41.

The square root of 666698 is about 816.5157683719. The cubic root of 666698 is about 87.3594150616.

The spelling of 666698 in words is "six hundred sixty-six thousand, six hundred ninety-eight".