666988560 has 320 divisors, whose sum is σ = 2712207360. Its totient is φ = 147432960.

The previous prime is 666988541. The next prime is 666988571. The reversal of 666988560 is 65889666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 666988497 and 666988506.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 468009 + ... + 469431.

It is an arithmetic number, because the mean of its divisors is an integer number (8475648).

Almost surely, 2^666988560 is an apocalyptic number.

666988560 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666988560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1356103680).

666988560 is an abundant number, since it is smaller than the sum of its proper divisors (2045218800).

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

666988560 is a wasteful number, since it uses less digits than its factorization.

666988560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1483 (or 1471 counting only the distinct ones).

The product of its (nonzero) digits is 3732480, while the sum is 54.

The square root of 666988560 is about 25826.1216600557. The cubic root of 666988560 is about 873.7210419772.

The spelling of 666988560 in words is "six hundred sixty-six million, nine hundred eighty-eight thousand, five hundred sixty".