921040 has 40 divisors (see below), whose sum is σ = 2220840. Its totient is φ = 354816.

The previous prime is 921031. The next prime is 921073. The reversal of 921040 is 40129.

It can be written as a sum of positive squares in 4 ways, for example, as 153664 + 767376 = 392^2 + 876^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

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, 2122 + ... + 2518.

It is an arithmetic number, because the mean of its divisors is an integer number (55521).

2⁹²¹⁰⁴⁰ 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 921040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1110420).

921040 is an abundant number, since it is smaller than the sum of its proper divisors (1299800).

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

921040 is a wasteful number, since it uses less digits than its factorization.

921040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 439 (or 433 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 921040 is about 959.7082890129. The cubic root of 921040 is about 97.2955170957.

Adding to 921040 its reverse (40129), we get a palindrome (961169).

The spelling of 921040 in words is "nine hundred twenty-one thousand, forty".