667225728 has 128 divisors (see below), whose sum is σ = 2120865600. Its totient is φ = 205286400.

The previous prime is 667225703. The next prime is 667225751. The reversal of 667225728 is 827522766.

667225728 is a `hidden beast` number, since 6 + 6 + 72 + 2 + 572 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (128).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37503 + ... + 52353.

Almost surely, 2^667225728 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 667225728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1060432800).

667225728 is an abundant number, since it is smaller than the sum of its proper divisors (1453639872).

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

667225728 is a wasteful number, since it uses less digits than its factorization.

667225728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14887 (or 14869 counting only the distinct ones).

The product of its digits is 564480, while the sum is 45.

The square root of 667225728 is about 25830.7128821486. The cubic root of 667225728 is about 873.8245890385.

It can be divided in two parts, 6672 and 25728, that added together give a square (32400 = 180²).

The spelling of 667225728 in words is "six hundred sixty-seven million, two hundred twenty-five thousand, seven hundred twenty-eight".