665740 has 12 divisors (see below), whose sum is σ = 1398096. Its totient is φ = 266288.

The previous prime is 665723. The next prime is 665747. The reversal of 665740 is 47566.

It is a plaindrome in base 14.

It is a junction number, because it is equal to n+sod(n) for n = 665699 and 665708.

It is not an unprimeable number, because it can be changed into a prime (665747) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16624 + ... + 16663.

It is an arithmetic number, because the mean of its divisors is an integer number (116508).

2⁶⁶⁵⁷⁴⁰ is an apocalyptic number.

It is an amenable number.

665740 is an abundant number, since it is smaller than the sum of its proper divisors (732356).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

665740 is a wasteful number, since it uses less digits than its factorization.

665740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33296 (or 33294 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 665740 is about 815.9289184727. The cubic root of 665740 is about 87.3175518104.

The spelling of 665740 in words is "six hundred sixty-five thousand, seven hundred forty".