666771072 has 128 divisors (see below), whose sum is σ = 1977592320. Its totient is φ = 197299200.

The previous prime is 666771037. The next prime is 666771089. The reversal of 666771072 is 270177666.

666771072 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, 179797 + ... + 183467.

It is an arithmetic number, because the mean of its divisors is an integer number (15449940).

Almost surely, 2^666771072 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 666771072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (988796160).

666771072 is an abundant number, since it is smaller than the sum of its proper divisors (1310821248).

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

666771072 is a wasteful number, since it uses less digits than its factorization.

666771072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3742 (or 3730 counting only the distinct ones).

The product of its (nonzero) digits is 148176, while the sum is 42.

The square root of 666771072 is about 25821.9106961510. The cubic root of 666771072 is about 873.6260655857.

The spelling of 666771072 in words is "six hundred sixty-six million, seven hundred seventy-one thousand, seventy-two".