668979755 has 8 divisors (see below), whose sum is σ = 807417072. Its totient is φ = 532089568.

The previous prime is 668979749. The next prime is 668979757. The reversal of 668979755 is 557979866.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 668979755 - 2⁶ = 668979691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (668979757) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 385829 + ... + 387558.

It is an arithmetic number, because the mean of its divisors is an integer number (100927134).

Almost surely, 2^668979755 is an apocalyptic number.

668979755 is a deficient number, since it is larger than the sum of its proper divisors (138437317).

668979755 is a wasteful number, since it uses less digits than its factorization.

668979755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 773565.

The product of its digits is 28576800, while the sum is 62.

The square root of 668979755 is about 25864.6429513342. The cubic root of 668979755 is about 874.5896328777.

The spelling of 668979755 in words is "six hundred sixty-eight million, nine hundred seventy-nine thousand, seven hundred fifty-five".