668405745 has 48 divisors (see below), whose sum is σ = 1401978240. Its totient is φ = 287580672.

The previous prime is 668405743. The next prime is 668405761. The reversal of 668405745 is 547504866.

It is not a de Polignac number, because 668405745 - 2¹ = 668405743 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 668405745.

It is not an unprimeable number, because it can be changed into a prime (668405743) 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 47 ways as a sum of consecutive naturals, for example, 57055 + ... + 67764.

It is an arithmetic number, because the mean of its divisors is an integer number (29207880).

Almost surely, 2^668405745 is an apocalyptic number.

It is an amenable number.

668405745 is an abundant number, since it is smaller than the sum of its proper divisors (733572495).

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

668405745 is a wasteful number, since it uses less digits than its factorization.

668405745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124854 (or 124851 counting only the distinct ones).

The product of its (nonzero) digits is 806400, while the sum is 45.

The square root of 668405745 is about 25853.5441477566. The cubic root of 668405745 is about 874.3394176084.

The spelling of 668405745 in words is "six hundred sixty-eight million, four hundred five thousand, seven hundred forty-five".