921666 has 8 divisors (see below), whose sum is σ = 1843344. Its totient is φ = 307220.

The previous prime is 921647. The next prime is 921667. The reversal of 921666 is 666129.

It is a sphenic number, since it is the product of 3 distinct primes.

921666 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (921667) 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, 76800 + ... + 76811.

It is an arithmetic number, because the mean of its divisors is an integer number (230418).

2⁹²¹⁶⁶⁶ is an apocalyptic number.

921666 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

921666 is a wasteful number, since it uses less digits than its factorization.

921666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153616.

The product of its digits is 3888, while the sum is 30.

The square root of 921666 is about 960.0343743846. The cubic root of 921666 is about 97.3175549370.

The spelling of 921666 in words is "nine hundred twenty-one thousand, six hundred sixty-six".