667543680 has 320 divisors, whose sum is σ = 2428905600. Its totient is φ = 174680064.

The previous prime is 667543619. The next prime is 667543693. The reversal of 667543680 is 86345766.

It is a tau number, because it is divible by the number of its divisors (320).

It is a super-2 number, since 2×667543680² = 891229129415884800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 4095279 + ... + 4095441.

It is an arithmetic number, because the mean of its divisors is an integer number (7590330).

Almost surely, 2^667543680 is an apocalyptic number.

667543680 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 667543680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1214452800).

667543680 is an abundant number, since it is smaller than the sum of its proper divisors (1761361920).

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

667543680 is a wasteful number, since it uses less digits than its factorization.

667543680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 273 (or 252 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 45.

The square root of 667543680 is about 25836.8666830945. The cubic root of 667543680 is about 873.9633677375.

The spelling of 667543680 in words is "six hundred sixty-seven million, five hundred forty-three thousand, six hundred eighty".