667811072 has 72 divisors (see below), whose sum is σ = 1439303040. Its totient is φ = 308295680.

The previous prime is 667811071. The next prime is 667811093. The reversal of 667811072 is 270118766.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667811071) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 168797 + ... + 172707.

It is an arithmetic number, because the mean of its divisors is an integer number (19990320).

Almost surely, 2^667811072 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 667811072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (719651520).

667811072 is an abundant number, since it is smaller than the sum of its proper divisors (771491968).

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

667811072 is a wasteful number, since it uses less digits than its factorization.

667811072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3979 (or 3965 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 38.

The square root of 667811072 is about 25842.0407862847. The cubic root of 667811072 is about 874.0800440561.

The spelling of 667811072 in words is "six hundred sixty-seven million, eight hundred eleven thousand, seventy-two".