660721552 has 20 divisors (see below), whose sum is σ = 1335807360. Its totient is φ = 315997088.

The previous prime is 660721549. The next prime is 660721553. The reversal of 660721552 is 255127066.

660721552 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 (660721553) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 897352 + ... + 898087.

It is an arithmetic number, because the mean of its divisors is an integer number (66790368).

Almost surely, 2^660721552 is an apocalyptic number.

It is an amenable number.

660721552 is an abundant number, since it is smaller than the sum of its proper divisors (675085808).

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

660721552 is a wasteful number, since it uses less digits than its factorization.

660721552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1795470 (or 1795464 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 34.

The square root of 660721552 is about 25704.5045079651. The cubic root of 660721552 is about 870.9759392068.

The spelling of 660721552 in words is "six hundred sixty million, seven hundred twenty-one thousand, five hundred fifty-two".