668746 has 24 divisors (see below), whose sum is σ = 1160460. Its totient is φ = 287232.

The previous prime is 668741. The next prime is 668747. The reversal of 668746 is 647866.

668746 is a nontrivial binomial coefficient, being equal to C(1157, 2).

It can be written as a sum of positive squares in 6 ways, for example, as 290521 + 378225 = 539^2 + 615^2 .

It is not an unprimeable number, because it can be changed into a prime (668741) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7470 + ... + 7558.

2⁶⁶⁸⁷⁴⁶ is an apocalyptic number.

668746 is the 1156-th triangular number.

668746 is the 386-th centered nonagonal number.

668746 is a deficient number, since it is larger than the sum of its proper divisors (491714).

668746 is a wasteful number, since it uses less digits than its factorization.

668746 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138 (or 121 counting only the distinct ones).

The product of its digits is 48384, while the sum is 37.

The square root of 668746 is about 817.7689160148. The cubic root of 668746 is about 87.4487754600.

The spelling of 668746 in words is "six hundred sixty-eight thousand, seven hundred forty-six".