921216 has 32 divisors (see below), whose sum is σ = 2448000. Its totient is φ = 306944.

The previous prime is 921203. The next prime is 921223. The reversal of 921216 is 612129.

It is a tau number, because it is divible by the number of its divisors (32).

It is an alternating number because its digits alternate between odd and even.

It is a junction number, because it is equal to n+sod(n) for n = 921192 and 921201.

It is a congruent number.

It is an unprimeable number.

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, 816 + ... + 1583.

It is an arithmetic number, because the mean of its divisors is an integer number (76500).

2⁹²¹²¹⁶ is an apocalyptic number.

921216 is a gapful number since it is divisible by the number (96) formed by its first and last digit.

It is an amenable number.

921216 is an abundant number, since it is smaller than the sum of its proper divisors (1526784).

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

921216 is a wasteful number, since it uses less digits than its factorization.

921216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2416 (or 2404 counting only the distinct ones).

The product of its digits is 216, while the sum is 21.

The square root of 921216 is about 959.7999791623. The cubic root of 921216 is about 97.3017140471.

The spelling of 921216 in words is "nine hundred twenty-one thousand, two hundred sixteen".