6813581 has 2 divisors, whose sum is σ = 6813582. Its totient is φ = 6813580.

The previous prime is 6813577. The next prime is 6813593. The reversal of 6813581 is 1853186.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6786025 + 27556 = 2605^2 + 166^2 .

It is a cyclic number.

It is not a de Polignac number, because 6813581 - 2² = 6813577 is a prime.

It is a super-2 number, since 2×6813581² = 92849772087122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6813511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3406790 + 3406791.

It is an arithmetic number, because the mean of its divisors is an integer number (3406791).

Almost surely, 2^6813581 is an apocalyptic number.

It is an amenable number.

6813581 is a deficient number, since it is larger than the sum of its proper divisors (1).

6813581 is an equidigital number, since it uses as much as digits as its factorization.

6813581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5760, while the sum is 32.

The square root of 6813581 is about 2610.2837010563. The cubic root of 6813581 is about 189.5796895434.

The spelling of 6813581 in words is "six million, eight hundred thirteen thousand, five hundred eighty-one".