667648 has 26 divisors (see below), whose sum is σ = 1343324. Its totient is φ = 331776.

The previous prime is 667643. The next prime is 667649. The reversal of 667648 is 846766.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (667643) by changing a digit.

667648 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 as a sum of consecutive naturals, namely, 4015 + ... + 4177.

2⁶⁶⁷⁶⁴⁸ 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 667648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (671662).

667648 is an abundant number, since it is smaller than the sum of its proper divisors (675676).

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

667648 is an equidigital number, since it uses as much as digits as its factorization.

667648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187 (or 165 counting only the distinct ones).

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

The square root of 667648 is about 817.0973014274. The cubic root of 667648 is about 87.4008891405.

It can be divided in two parts, 6676 and 48, that added together give a square (6724 = 82²).

The spelling of 667648 in words is "six hundred sixty-seven thousand, six hundred forty-eight".