667776 has 64 divisors (see below), whose sum is σ = 1860480. Its totient is φ = 211968.

The previous prime is 667769. The next prime is 667781. The reversal of 667776 is 677766.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-3 number, since 3×667776³ = 893333610040393728, which contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

667776 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 7 ways as a sum of consecutive naturals, for example, 14185 + ... + 14231.

It is an arithmetic number, because the mean of its divisors is an integer number (29070).

2⁶⁶⁷⁷⁷⁶ 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 667776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (930240).

667776 is an abundant number, since it is smaller than the sum of its proper divisors (1192704).

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

667776 is a wasteful number, since it uses less digits than its factorization.

667776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101 (or 89 counting only the distinct ones).

The product of its digits is 74088, while the sum is 39.

The square root of 667776 is about 817.1756237187. The cubic root of 667776 is about 87.4064742187.

The spelling of 667776 in words is "six hundred sixty-seven thousand, seven hundred seventy-six".