669658 has 16 divisors (see below), whose sum is σ = 1116000. Its totient is φ = 298800.

The previous prime is 669649. The next prime is 669659. The reversal of 669658 is 856966.

669658 is nontrivially palindromic in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 669658.

It is not an unprimeable number, because it can be changed into a prime (669659) 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, 1093 + ... + 1591.

It is an arithmetic number, because the mean of its divisors is an integer number (69750).

2⁶⁶⁹⁶⁵⁸ is an apocalyptic number.

669658 is a deficient number, since it is larger than the sum of its proper divisors (446342).

669658 is a wasteful number, since it uses less digits than its factorization.

669658 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 573.

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

The square root of 669658 is about 818.3263407712. The cubic root of 669658 is about 87.4885100559.

The spelling of 669658 in words is "six hundred sixty-nine thousand, six hundred fifty-eight".