133581661586861 has 2 divisors, whose sum is σ = 133581661586862. Its totient is φ = 133581661586860.

The previous prime is 133581661586839. The next prime is 133581661586887. The reversal of 133581661586861 is 168685166185331.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 123588356020900 + 9993305565961 = 11117030^2 + 3161219^2 .

It is a cyclic number.

It is not a de Polignac number, because 133581661586861 - 2²⁶ = 133581594477997 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 133581661586791 and 133581661586800.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (133581661583861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66790830793430 + 66790830793431.

It is an arithmetic number, because the mean of its divisors is an integer number (66790830793431).

Almost surely, 2^{133581661586861} is an apocalyptic number.

It is an amenable number.

133581661586861 is a deficient number, since it is larger than the sum of its proper divisors (1).

133581661586861 is an equidigital number, since it uses as much as digits as its factorization.

133581661586861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 149299200, while the sum is 68.

The spelling of 133581661586861 in words is "one hundred thirty-three trillion, five hundred eighty-one billion, six hundred sixty-one million, five hundred eighty-six thousand, eight hundred sixty-one".