665412 has 36 divisors (see below), whose sum is σ = 1717968. Its totient is φ = 198800.

The previous prime is 665387. The next prime is 665419. The reversal of 665412 is 214566.

It is an Ulam number.

Its product of digits (1440) is a multiple of the sum of its prime factors (160).

It is not an unprimeable number, because it can be changed into a prime (665419) by changing a digit.

665412 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9337 + ... + 9407.

2⁶⁶⁵⁴¹² is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 665412, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (858984).

665412 is an abundant number, since it is smaller than the sum of its proper divisors (1052556).

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

665412 is a wasteful number, since it uses less digits than its factorization.

665412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160 (or 87 counting only the distinct ones).

The product of its digits is 1440, while the sum is 24.

The square root of 665412 is about 815.7278958084. The cubic root of 665412 is about 87.3032094436.

Adding to 665412 its reverse (214566), we get a palindrome (879978).

It can be divided in two parts, 6654 and 12, that added together give a palindrome (6666).

The spelling of 665412 in words is "six hundred sixty-five thousand, four hundred twelve".