666653760 has 448 divisors, whose sum is σ = 2574950400. Its totient is φ = 161740800.

The previous prime is 666653749. The next prime is 666653773. The reversal of 666653760 is 67356666.

It is a happy number.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5088895 + ... + 5089025.

Almost surely, 2^666653760 is an apocalyptic number.

666653760 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 666653760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1287475200).

666653760 is an abundant number, since it is smaller than the sum of its proper divisors (1908296640).

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

666653760 is a wasteful number, since it uses less digits than its factorization.

666653760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207 (or 191 counting only the distinct ones).

The product of its (nonzero) digits is 816480, while the sum is 45.

The square root of 666653760 is about 25819.6390369811. The cubic root of 666653760 is about 873.5748271940.

The spelling of 666653760 in words is "six hundred sixty-six million, six hundred fifty-three thousand, seven hundred sixty".