666513 has 12 divisors (see below), whose sum is σ = 973440. Its totient is φ = 439416.

The previous prime is 666511. The next prime is 666527. The reversal of 666513 is 315666.

It is not a de Polignac number, because 666513 - 2¹ = 666511 is a prime.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

666513 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (666511) 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, 568 + ... + 1286.

It is an arithmetic number, because the mean of its divisors is an integer number (81120).

2⁶⁶⁶⁵¹³ is an apocalyptic number.

It is an amenable number.

666513 is a deficient number, since it is larger than the sum of its proper divisors (306927).

666513 is a wasteful number, since it uses less digits than its factorization.

666513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 828 (or 825 counting only the distinct ones).

The product of its digits is 3240, while the sum is 27.

The square root of 666513 is about 816.4024742736. The cubic root of 666513 is about 87.3513339480.

The spelling of 666513 in words is "six hundred sixty-six thousand, five hundred thirteen".