667440664 has 128 divisors (see below), whose sum is σ = 1511424000. Its totient is φ = 272937600.

The previous prime is 667440661. The next prime is 667440673. The reversal of 667440664 is 466044766.

It is a self number, because there is not a number n which added to its sum of digits gives 667440664.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667440661) 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 31 ways as a sum of consecutive naturals, for example, 4094647 + ... + 4094809.

It is an arithmetic number, because the mean of its divisors is an integer number (11808000).

Almost surely, 2^667440664 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 667440664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (755712000).

667440664 is an abundant number, since it is smaller than the sum of its proper divisors (843983336).

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

667440664 is a wasteful number, since it uses less digits than its factorization.

667440664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309 (or 305 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 43.

The square root of 667440664 is about 25834.8730207834. The cubic root of 667440664 is about 873.9184084613.

The spelling of 667440664 in words is "six hundred sixty-seven million, four hundred forty thousand, six hundred sixty-four".