666505756 has 24 divisors (see below), whose sum is σ = 1335108096. Its totient is φ = 285196080.

The previous prime is 666505747. The next prime is 666505771. The reversal of 666505756 is 657505666.

It is a super-2 number, since 2×666505756² = 888459845562263072, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 280 + ... + 36511.

It is an arithmetic number, because the mean of its divisors is an integer number (55629504).

Almost surely, 2^666505756 is an apocalyptic number.

It is an amenable number.

666505756 is an abundant number, since it is smaller than the sum of its proper divisors (668602340).

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

666505756 is a wasteful number, since it uses less digits than its factorization.

666505756 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37449 (or 37447 counting only the distinct ones).

The product of its (nonzero) digits is 1134000, while the sum is 46.

The square root of 666505756 is about 25816.7727650069. The cubic root of 666505756 is about 873.5101748733.

The spelling of 666505756 in words is "six hundred sixty-six million, five hundred five thousand, seven hundred fifty-six".