665725726636 has 24 divisors (see below), whose sum is σ = 1167274644480. Its totient is φ = 332219191632.

The previous prime is 665725726613. The next prime is 665725726639. The reversal of 665725726636 is 636627527566.

It is not an unprimeable number, because it can be changed into a prime (665725726639) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5307501 + ... + 5431483.

It is an arithmetic number, because the mean of its divisors is an integer number (48636443520).

Almost surely, 2^665725726636 is an apocalyptic number.

It is an amenable number.

665725726636 is a deficient number, since it is larger than the sum of its proper divisors (501548917844).

665725726636 is a wasteful number, since it uses less digits than its factorization.

665725726636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126573 (or 126571 counting only the distinct ones).

The product of its digits is 114307200, while the sum is 61.

The spelling of 665725726636 in words is "six hundred sixty-five billion, seven hundred twenty-five million, seven hundred twenty-six thousand, six hundred thirty-six".