921856 has 36 divisors (see below), whose sum is σ = 1988812. Its totient is φ = 423936.

The previous prime is 921841. The next prime is 921871. The reversal of 921856 is 658129.

It is an interprime number because it is at equal distance from previous prime (921841) and next prime (921871).

It can be written as a sum of positive squares in 2 ways, for example, as 147456 + 774400 = 384^2 + 880^2 .

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

It is a nialpdrome in base 16.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3190 + ... + 3466.

2⁹²¹⁸⁵⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 921856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (994406).

921856 is an abundant number, since it is smaller than the sum of its proper divisors (1066956).

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

921856 is a wasteful number, since it uses less digits than its factorization.

921856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 306 (or 292 counting only the distinct ones).

The product of its digits is 4320, while the sum is 31.

The square root of 921856 is about 960.1333240754. The cubic root of 921856 is about 97.3242417646.

The spelling of 921856 in words is "nine hundred twenty-one thousand, eight hundred fifty-six".