6559981 has 2 divisors, whose sum is σ = 6559982. Its totient is φ = 6559980.

The previous prime is 6559963. The next prime is 6560017. The reversal of 6559981 is 1899556.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3553225 + 3006756 = 1885^2 + 1734^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6559981 is a prime.

It is a super-2 number, since 2×6559981² = 86066701440722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6559901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3279990 + 3279991.

It is an arithmetic number, because the mean of its divisors is an integer number (3279991).

Almost surely, 2^6559981 is an apocalyptic number.

It is an amenable number.

6559981 is a deficient number, since it is larger than the sum of its proper divisors (1).

6559981 is an equidigital number, since it uses as much as digits as its factorization.

6559981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 97200, while the sum is 43.

The square root of 6559981 is about 2561.2459858436. The cubic root of 6559981 is about 187.1978517328.

The spelling of 6559981 in words is "six million, five hundred fifty-nine thousand, nine hundred eighty-one".