661666508 has 12 divisors (see below), whose sum is σ = 1158165960. Its totient is φ = 330761952.

The previous prime is 661666501. The next prime is 661666513. The reversal of 661666508 is 805666166.

661666508 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (661666501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6848 + ... + 37016.

It is an arithmetic number, because the mean of its divisors is an integer number (96513830).

Almost surely, 2^661666508 is an apocalyptic number.

It is an amenable number.

661666508 is a deficient number, since it is larger than the sum of its proper divisors (496499452).

661666508 is a wasteful number, since it uses less digits than its factorization.

661666508 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35656 (or 35654 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 44.

The square root of 661666508 is about 25722.8790768063. The cubic root of 661666508 is about 871.3909611799.

The spelling of 661666508 in words is "six hundred sixty-one million, six hundred sixty-six thousand, five hundred eight".