667710720 has 216 divisors, whose sum is σ = 2331693000. Its totient is φ = 176406528.

The previous prime is 667710661. The next prime is 667710721. The reversal of 667710720 is 27017766.

It can be written as a sum of positive squares in 4 ways, for example, as 831744 + 666878976 = 912^2 + 25824^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667710721) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 1716286 + ... + 1716674.

It is an arithmetic number, because the mean of its divisors is an integer number (10794875).

Almost surely, 2^667710720 is an apocalyptic number.

667710720 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 667710720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1165846500).

667710720 is an abundant number, since it is smaller than the sum of its proper divisors (1663982280).

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

667710720 is a wasteful number, since it uses less digits than its factorization.

667710720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 565 (or 548 counting only the distinct ones).

The product of its (nonzero) digits is 24696, while the sum is 36.

The square root of 667710720 is about 25840.0990710175. The cubic root of 667710720 is about 874.0362591803.

The spelling of 667710720 in words is "six hundred sixty-seven million, seven hundred ten thousand, seven hundred twenty".