668971 has 8 divisors (see below), whose sum is σ = 712080. Its totient is φ = 626688.

The previous prime is 668963. The next prime is 668989. The reversal of 668971 is 179866.

668971 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 668971 - 2³ = 668963 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 668971.

It is not an unprimeable number, because it can be changed into a prime (668471) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2475 + ... + 2731.

It is an arithmetic number, because the mean of its divisors is an integer number (89010).

2⁶⁶⁸⁹⁷¹ is an apocalyptic number.

668971 is a deficient number, since it is larger than the sum of its proper divisors (43109).

668971 is a wasteful number, since it uses less digits than its factorization.

668971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 413.

The product of its digits is 18144, while the sum is 37.

The square root of 668971 is about 817.9064738709. The cubic root of 668971 is about 87.4585817583.

The spelling of 668971 in words is "six hundred sixty-eight thousand, nine hundred seventy-one".