667720872 has 192 divisors, whose sum is σ = 2240609280. Its totient is φ = 174928896.

The previous prime is 667720831. The next prime is 667720891. The reversal of 667720872 is 278027766.

It is a happy number.

667720872 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1460868 + ... + 1461324.

It is an arithmetic number, because the mean of its divisors is an integer number (11669840).

Almost surely, 2^667720872 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 667720872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1120304640).

667720872 is an abundant number, since it is smaller than the sum of its proper divisors (1572888408).

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

667720872 is a wasteful number, since it uses less digits than its factorization.

667720872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 712 (or 705 counting only the distinct ones).

The product of its (nonzero) digits is 395136, while the sum is 45.

The square root of 667720872 is about 25840.2955091462. The cubic root of 667720872 is about 874.0406888286.

The spelling of 667720872 in words is "six hundred sixty-seven million, seven hundred twenty thousand, eight hundred seventy-two".