668836345 has 4 divisors (see below), whose sum is σ = 802603620. Its totient is φ = 535069072.

The previous prime is 668836339. The next prime is 668836361. The reversal of 668836345 is 543638866.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 284833129 + 384003216 = 16877^2 + 19596^2 .

It is a cyclic number.

It is not a de Polignac number, because 668836345 - 2⁵ = 668836313 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 66883630 + ... + 66883639.

It is an arithmetic number, because the mean of its divisors is an integer number (200650905).

Almost surely, 2^668836345 is an apocalyptic number.

It is an amenable number.

668836345 is a deficient number, since it is larger than the sum of its proper divisors (133767275).

668836345 is a wasteful number, since it uses less digits than its factorization.

668836345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133767274.

The product of its digits is 2488320, while the sum is 49.

The square root of 668836345 is about 25861.8704853303. The cubic root of 668836345 is about 874.5271327986.

The spelling of 668836345 in words is "six hundred sixty-eight million, eight hundred thirty-six thousand, three hundred forty-five".