668771 has 4 divisors (see below), whose sum is σ = 697872. Its totient is φ = 639672.

The previous prime is 668761. The next prime is 668791. The reversal of 668771 is 177866.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-668771 is a prime.

It is a Duffinian number.

It is a zygodrome in base 6.

It is not an unprimeable number, because it can be changed into a prime (668741) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14516 + ... + 14561.

It is an arithmetic number, because the mean of its divisors is an integer number (174468).

2⁶⁶⁸⁷⁷¹ is an apocalyptic number.

668771 is a deficient number, since it is larger than the sum of its proper divisors (29101).

668771 is a wasteful number, since it uses less digits than its factorization.

668771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29100.

The product of its digits is 14112, while the sum is 35.

The square root of 668771 is about 817.7842013637. The cubic root of 668771 is about 87.4498651573.

The spelling of 668771 in words is "six hundred sixty-eight thousand, seven hundred seventy-one".