667680 has 96 divisors (see below), whose sum is σ = 2286144. Its totient is φ = 162816.

The previous prime is 667673. The next prime is 667687. The reversal of 667680 is 86766.

It is an interprime number because it is at equal distance from previous prime (667673) and next prime (667687).

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (667687) by changing a digit.

667680 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6187 + ... + 6293.

It is an arithmetic number, because the mean of its divisors is an integer number (23814).

2⁶⁶⁷⁶⁸⁰ is an apocalyptic number.

667680 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 667680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1143072).

667680 is an abundant number, since it is smaller than the sum of its proper divisors (1618464).

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

667680 is a wasteful number, since it uses less digits than its factorization.

667680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138 (or 130 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 33.

The square root of 667680 is about 817.1168827041. The cubic root of 667680 is about 87.4022854770.

The spelling of 667680 in words is "six hundred sixty-seven thousand, six hundred eighty".