660220644 has 24 divisors (see below), whose sum is σ = 1541746080. Its totient is φ = 219897664.

The previous prime is 660220643. The next prime is 660220657. The reversal of 660220644 is 446022066.

660220644 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (660220643) 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, 5874 + ... + 36809.

It is an arithmetic number, because the mean of its divisors is an integer number (64239420).

Almost surely, 2^660220644 is an apocalyptic number.

It is an amenable number.

660220644 is an abundant number, since it is smaller than the sum of its proper divisors (881525436).

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

660220644 is a wasteful number, since it uses less digits than its factorization.

660220644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43979 (or 43977 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 30.

The square root of 660220644 is about 25694.7590765121. The cubic root of 660220644 is about 870.7557813547.

The spelling of 660220644 in words is "six hundred sixty million, two hundred twenty thousand, six hundred forty-four".