667723840 has 224 divisors, whose sum is σ = 1982419200. Its totient is φ = 209018880.

The previous prime is 667723813. The next prime is 667723871. The reversal of 667723840 is 48327766.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (224).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1233970 + ... + 1234510.

Almost surely, 2^667723840 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 667723840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (991209600).

667723840 is an abundant number, since it is smaller than the sum of its proper divisors (1314695360).

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

667723840 is a wasteful number, since it uses less digits than its factorization.

667723840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 613 (or 603 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 43.

The square root of 667723840 is about 25840.3529387661. The cubic root of 667723840 is about 874.0419838553.

The spelling of 667723840 in words is "six hundred sixty-seven million, seven hundred twenty-three thousand, eight hundred forty".