6581321 has 2 divisors, whose sum is σ = 6581322. Its totient is φ = 6581320.

The previous prime is 6581317. The next prime is 6581327. The reversal of 6581321 is 1231856.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6574096 + 7225 = 2564^2 + 85^2 .

It is a cyclic number.

It is not a de Polignac number, because 6581321 - 2² = 6581317 is a prime.

It is a super-2 number, since 2×6581321² = 86627572210082, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (6581327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3290660 + 3290661.

It is an arithmetic number, because the mean of its divisors is an integer number (3290661).

Almost surely, 2^6581321 is an apocalyptic number.

It is an amenable number.

6581321 is a deficient number, since it is larger than the sum of its proper divisors (1).

6581321 is an equidigital number, since it uses as much as digits as its factorization.

6581321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1440, while the sum is 26.

The square root of 6581321 is about 2565.4085444623. The cubic root of 6581321 is about 187.4006205210.

The spelling of 6581321 in words is "six million, five hundred eighty-one thousand, three hundred twenty-one".