666064487556 has 72 divisors (see below), whose sum is σ = 1814932119000. Its totient is φ = 204744374784.

The previous prime is 666064487533. The next prime is 666064487623. The reversal of 666064487556 is 655784460666.

It can be written as a sum of positive squares in 4 ways, for example, as 148217300100 + 517847187456 = 384990^2 + 719616^2 .

It is a junction number, because it is equal to n+sod(n) for n = 666064487493 and 666064487502.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 205431 + ... + 1172318.

Almost surely, 2^666064487556 is an apocalyptic number.

It is an amenable number.

666064487556 is an abundant number, since it is smaller than the sum of its proper divisors (1148867631444).

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

666064487556 is a wasteful number, since it uses less digits than its factorization.

666064487556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1378805 (or 1378800 counting only the distinct ones).

The product of its (nonzero) digits is 174182400, while the sum is 63.

The spelling of 666064487556 in words is "six hundred sixty-six billion, sixty-four million, four hundred eighty-seven thousand, five hundred fifty-six".