6581633331281 has 2 divisors, whose sum is σ = 6581633331282. Its totient is φ = 6581633331280.

The previous prime is 6581633331277. The next prime is 6581633331283. The reversal of 6581633331281 is 1821333361856.

6581633331281 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6482543735056 + 99089596225 = 2546084^2 + 314785^2 .

It is a cyclic number.

It is not a de Polignac number, because 6581633331281 - 2² = 6581633331277 is a prime.

It is a super-2 number, since 2×6581633331281² (a number of 26 digits) contains 22 as substring.

Together with 6581633331283, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (6581633331283) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3290816665640 + 3290816665641.

It is an arithmetic number, because the mean of its divisors is an integer number (3290816665641).

Almost surely, 2^{6581633331281} is an apocalyptic number.

It is an amenable number.

6581633331281 is a deficient number, since it is larger than the sum of its proper divisors (1).

6581633331281 is an equidigital number, since it uses as much as digits as its factorization.

6581633331281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1866240, while the sum is 50.

The spelling of 6581633331281 in words is "six trillion, five hundred eighty-one billion, six hundred thirty-three million, three hundred thirty-one thousand, two hundred eighty-one".