668560749 has 8 divisors (see below), whose sum is σ = 896567712. Its totient is φ = 443130480.

The previous prime is 668560747. The next prime is 668560777. The reversal of 668560749 is 947065866.

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

It is not a de Polignac number, because 668560749 - 2¹ = 668560747 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668560747) 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, 643567 + ... + 644604.

It is an arithmetic number, because the mean of its divisors is an integer number (112070964).

Almost surely, 2^668560749 is an apocalyptic number.

It is an amenable number.

668560749 is a deficient number, since it is larger than the sum of its proper divisors (228006963).

668560749 is a wasteful number, since it uses less digits than its factorization.

668560749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1288347.

The product of its (nonzero) digits is 2177280, while the sum is 51.

The square root of 668560749 is about 25856.5417061138. The cubic root of 668560749 is about 874.4069991302.

The spelling of 668560749 in words is "six hundred sixty-eight million, five hundred sixty thousand, seven hundred forty-nine".