665660136888544 has 24 divisors (see below), whose sum is σ = 1497735307999728. Its totient is φ = 285282915809280.

The previous prime is 665660136888521. The next prime is 665660136888587. The reversal of 665660136888544 is 445888631066566.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1485848519617 + ... + 1485848520064.

It is an arithmetic number, because the mean of its divisors is an integer number (62405637833322).

Almost surely, 2^{665660136888544} is an apocalyptic number.

It is an amenable number.

665660136888544 is an abundant number, since it is smaller than the sum of its proper divisors (832075171111184).

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

665660136888544 is a wasteful number, since it uses less digits than its factorization.

665660136888544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2971697039698 (or 2971697039690 counting only the distinct ones).

The product of its (nonzero) digits is 4777574400, while the sum is 76.

The spelling of 665660136888544 in words is "six hundred sixty-five trillion, six hundred sixty billion, one hundred thirty-six million, eight hundred eighty-eight thousand, five hundred forty-four".