6618581 has 2 divisors, whose sum is σ = 6618582. Its totient is φ = 6618580.

The previous prime is 6618569. The next prime is 6618617. The reversal of 6618581 is 1858166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6584356 + 34225 = 2566^2 + 185^2 .

It is a cyclic number.

It is not a de Polignac number, because 6618581 - 2¹⁰ = 6617557 is a prime.

It is a super-2 number, since 2×6618581² = 87611228907122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6618511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3309290 + 3309291.

It is an arithmetic number, because the mean of its divisors is an integer number (3309291).

Almost surely, 2^6618581 is an apocalyptic number.

It is an amenable number.

6618581 is a deficient number, since it is larger than the sum of its proper divisors (1).

6618581 is an equidigital number, since it uses as much as digits as its factorization.

6618581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11520, while the sum is 35.

The square root of 6618581 is about 2572.6602962692. The cubic root of 6618581 is about 187.7536100010.

It can be divided in two parts, 66185 and 81, that added together give a palindrome (66266).

The spelling of 6618581 in words is "six million, six hundred eighteen thousand, five hundred eighty-one".