921440 has 48 divisors (see below), whose sum is σ = 2349648. Its totient is φ = 339456.

The previous prime is 921409. The next prime is 921457. The reversal of 921440 is 44129.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 921440.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1859 + ... + 2301.

It is an arithmetic number, because the mean of its divisors is an integer number (48951).

2⁹²¹⁴⁴⁰ 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 921440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1174824).

921440 is an abundant number, since it is smaller than the sum of its proper divisors (1428208).

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

921440 is a wasteful number, since it uses less digits than its factorization.

921440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 471 (or 463 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 921440 is about 959.9166630495. The cubic root of 921440 is about 97.3095999347.

Adding to 921440 its reverse (44129), we get a palindrome (965569).

The spelling of 921440 in words is "nine hundred twenty-one thousand, four hundred forty".