7321520 has 40 divisors (see below), whose sum is σ = 17275680. Its totient is φ = 2885120.

The previous prime is 7321507. The next prime is 7321529. The reversal of 7321520 is 251237.

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

It is a super-2 number, since 2×7321520² = 107209310220800, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 7321492 and 7321501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7321529) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5036 + ... + 6324.

It is an arithmetic number, because the mean of its divisors is an integer number (431892).

Almost surely, 2^7321520 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 7321520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8637840).

7321520 is an abundant number, since it is smaller than the sum of its proper divisors (9954160).

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

7321520 is a wasteful number, since it uses less digits than its factorization.

7321520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1373 (or 1367 counting only the distinct ones).

The product of its (nonzero) digits is 420, while the sum is 20.

The square root of 7321520 is about 2705.8307411958. The cubic root of 7321520 is about 194.1781761942.

Adding to 7321520 its reverse (251237), we get a palindrome (7572757).

The spelling of 7321520 in words is "seven million, three hundred twenty-one thousand, five hundred twenty".