660766 has 4 divisors (see below), whose sum is σ = 991152. Its totient is φ = 330382.

The previous prime is 660757. The next prime is 660769. The reversal of 660766 is 667066.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 667066 = 2 ⋅333533.

It is a super-2 number, since 2×660766² = 873223413512, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165190 + ... + 165193.

It is an arithmetic number, because the mean of its divisors is an integer number (247788).

2⁶⁶⁰⁷⁶⁶ is an apocalyptic number.

660766 is the 435-th centered heptagonal number.

660766 is a deficient number, since it is larger than the sum of its proper divisors (330386).

660766 is a wasteful number, since it uses less digits than its factorization.

660766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330385.

The product of its (nonzero) digits is 9072, while the sum is 31.

The square root of 660766 is about 812.8751441642. The cubic root of 660766 is about 87.0995469507.

The spelling of 660766 in words is "six hundred sixty thousand, seven hundred sixty-six".