6561481 has 2 divisors, whose sum is σ = 6561482. Its totient is φ = 6561480.

The previous prime is 6561461. The next prime is 6561493. The reversal of 6561481 is 1841656.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5593225 + 968256 = 2365^2 + 984^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6561481 is a prime.

It is a super-2 number, since 2×6561481² = 86106065826722, which contains 22 as substring.

It is a Chen prime.

It is an Ulam number.

6561481 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (6561461) 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, 3280740 + 3280741.

It is an arithmetic number, because the mean of its divisors is an integer number (3280741).

Almost surely, 2^6561481 is an apocalyptic number.

It is an amenable number.

6561481 is a deficient number, since it is larger than the sum of its proper divisors (1).

6561481 is an equidigital number, since it uses as much as digits as its factorization.

6561481 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5760, while the sum is 31.

The square root of 6561481 is about 2561.5387953338. The cubic root of 6561481 is about 187.2121188157.

The spelling of 6561481 in words is "six million, five hundred sixty-one thousand, four hundred eighty-one".