668171543 has 4 divisors (see below), whose sum is σ = 719569368. Its totient is φ = 616773720.

The previous prime is 668171533. The next prime is 668171563. The reversal of 668171543 is 345171866.

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

It is a cyclic number.

It is not a de Polignac number, because 668171543 - 2¹⁰ = 668170519 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 668171543.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668171533) 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 3 ways as a sum of consecutive naturals, for example, 25698893 + ... + 25698918.

It is an arithmetic number, because the mean of its divisors is an integer number (179892342).

Almost surely, 2^668171543 is an apocalyptic number.

668171543 is a deficient number, since it is larger than the sum of its proper divisors (51397825).

668171543 is a wasteful number, since it uses less digits than its factorization.

668171543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51397824.

The product of its digits is 120960, while the sum is 41.

The square root of 668171543 is about 25849.0143525822. The cubic root of 668171543 is about 874.2372860498.

The spelling of 668171543 in words is "six hundred sixty-eight million, one hundred seventy-one thousand, five hundred forty-three".