666635760 has 240 divisors, whose sum is σ = 2647419840. Its totient is φ = 147087360.

The previous prime is 666635759. The next prime is 666635779. The reversal of 666635760 is 67536666.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (240).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 143880 + ... + 148440.

It is an arithmetic number, because the mean of its divisors is an integer number (11030916).

Almost surely, 2^666635760 is an apocalyptic number.

666635760 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 666635760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1323709920).

666635760 is an abundant number, since it is smaller than the sum of its proper divisors (1980784080).

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

666635760 is a wasteful number, since it uses less digits than its factorization.

666635760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4616 (or 4607 counting only the distinct ones).

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

The square root of 666635760 is about 25819.2904627528. The cubic root of 666635760 is about 873.5669647976.

The spelling of 666635760 in words is "six hundred sixty-six million, six hundred thirty-five thousand, seven hundred sixty".