921644 has 12 divisors (see below), whose sum is σ = 1629264. Its totient is φ = 456144.

The previous prime is 921643. The next prime is 921647. The reversal of 921644 is 446129.

It is not an unprimeable number, because it can be changed into a prime (921643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 707 + ... + 1530.

It is an arithmetic number, because the mean of its divisors is an integer number (135772).

2⁹²¹⁶⁴⁴ is an apocalyptic number.

It is an amenable number.

921644 is a deficient number, since it is larger than the sum of its proper divisors (707620).

921644 is a wasteful number, since it uses less digits than its factorization.

921644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2344 (or 2342 counting only the distinct ones).

The product of its digits is 1728, while the sum is 26.

The square root of 921644 is about 960.0229163931. The cubic root of 921644 is about 97.3167806134.

It can be divided in two parts, 9216 and 44, that multiplied together give a palindrome (405504).

The spelling of 921644 in words is "nine hundred twenty-one thousand, six hundred forty-four".