7321440 has 96 divisors (see below), whose sum is σ = 26369280. Its totient is φ = 1672704.

The previous prime is 7321439. The next prime is 7321451. The reversal of 7321440 is 441237.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2271 + ... + 4449.

It is an arithmetic number, because the mean of its divisors is an integer number (274680).

Almost surely, 2^7321440 is an apocalyptic number.

7321440 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7321440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13184640).

7321440 is an abundant number, since it is smaller than the sum of its proper divisors (19047840).

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

7321440 is a wasteful number, since it uses less digits than its factorization.

7321440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2204 (or 2196 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 21.

The square root of 7321440 is about 2705.8159582647. The cubic root of 7321440 is about 194.1774689498.

Adding to 7321440 its reverse (441237), we get a palindrome (7762677).

The spelling of 7321440 in words is "seven million, three hundred twenty-one thousand, four hundred forty".