7320521 has 4 divisors (see below), whose sum is σ = 7883652. Its totient is φ = 6757392.

The previous prime is 7320503. The next prime is 7320527. The reversal of 7320521 is 1250237.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4644025 + 2676496 = 2155^2 + 1636^2 .

It is a cyclic number.

It is not a de Polignac number, because 7320521 - 2¹⁴ = 7304137 is a prime.

It is a super-2 number, since 2×7320521² = 107180055422882, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 7320493 and 7320502.

It is not an unprimeable number, because it can be changed into a prime (7320527) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 281546 + ... + 281571.

It is an arithmetic number, because the mean of its divisors is an integer number (1970913).

Almost surely, 2^7320521 is an apocalyptic number.

It is an amenable number.

7320521 is a deficient number, since it is larger than the sum of its proper divisors (563131).

7320521 is a wasteful number, since it uses less digits than its factorization.

7320521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 563130.

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

The square root of 7320521 is about 2705.6461335511. The cubic root of 7320521 is about 194.1693441110.

Adding to 7320521 its reverse (1250237), we get a palindrome (8570758).

The spelling of 7320521 in words is "seven million, three hundred twenty thousand, five hundred twenty-one".