668349756 has 18 divisors (see below), whose sum is σ = 1689439752. Its totient is φ = 222783240.

The previous prime is 668349749. The next prime is 668349761. The reversal of 668349756 is 657943866.

It is a tau number, because it is divible by the number of its divisors (18).

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 5 ways as a sum of consecutive naturals, for example, 9282600 + ... + 9282671.

It is an arithmetic number, because the mean of its divisors is an integer number (93857764).

Almost surely, 2^668349756 is an apocalyptic number.

It is an amenable number.

668349756 is an abundant number, since it is smaller than the sum of its proper divisors (1021089996).

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

668349756 is a wasteful number, since it uses less digits than its factorization.

668349756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18565281 (or 18565276 counting only the distinct ones).

The product of its digits is 6531840, while the sum is 54.

The square root of 668349756 is about 25852.4613141573. The cubic root of 668349756 is about 874.3150039161.

The spelling of 668349756 in words is "six hundred sixty-eight million, three hundred forty-nine thousand, seven hundred fifty-six".