891668 has 12 divisors (see below), whose sum is σ = 1598772. Its totient is φ = 434880.

The previous prime is 891661. The next prime is 891677. The reversal of 891668 is 866198.

891668 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 232324 + 659344 = 482^2 + 812^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (891661) 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, 2555 + ... + 2882.

It is an arithmetic number, because the mean of its divisors is an integer number (133231).

2⁸⁹¹⁶⁶⁸ is an apocalyptic number.

It is an amenable number.

891668 is a deficient number, since it is larger than the sum of its proper divisors (707104).

891668 is a wasteful number, since it uses less digits than its factorization.

891668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5482 (or 5480 counting only the distinct ones).

The product of its digits is 20736, while the sum is 38.

The square root of 891668 is about 944.2817376186. The cubic root of 891668 is about 96.2500714004.

The spelling of 891668 in words is "eight hundred ninety-one thousand, six hundred sixty-eight".