7813321 has 4 divisors (see below), whose sum is σ = 7821700. Its totient is φ = 7804944.

The previous prime is 7813303. The next prime is 7813331. The reversal of 7813321 is 1233187.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 3553225 + 4260096 = 1885^2 + 2064^2 .

It is a cyclic number.

It is not a de Polignac number, because 7813321 - 2¹⁹ = 7289033 is a prime.

It is a super-2 number, since 2×7813321² = 122095970098082, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7813301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2586 + ... + 4723.

It is an arithmetic number, because the mean of its divisors is an integer number (1955425).

Almost surely, 2^7813321 is an apocalyptic number.

It is an amenable number.

7813321 is a deficient number, since it is larger than the sum of its proper divisors (8379).

7813321 is a wasteful number, since it uses less digits than its factorization.

7813321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8378.

The product of its digits is 1008, while the sum is 25.

The square root of 7813321 is about 2795.2318329613. The cubic root of 7813321 is about 198.4320819526.

The spelling of 7813321 in words is "seven million, eight hundred thirteen thousand, three hundred twenty-one".