1361202216581 has 2 divisors, whose sum is σ = 1361202216582. Its totient is φ = 1361202216580.

The previous prime is 1361202216571. The next prime is 1361202216617. The reversal of 1361202216581 is 1856122021631.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1040738667556 + 320463549025 = 1020166^2 + 566095^2 .

It is a cyclic number.

It is not a de Polignac number, because 1361202216581 - 2²² = 1361198022277 is a prime.

It is a super-2 number, since 2×1361202216581² (a number of 25 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1361202216571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 680601108290 + 680601108291.

It is an arithmetic number, because the mean of its divisors is an integer number (680601108291).

Almost surely, 2^{1361202216581} is an apocalyptic number.

It is an amenable number.

1361202216581 is a deficient number, since it is larger than the sum of its proper divisors (1).

1361202216581 is an equidigital number, since it uses as much as digits as its factorization.

1361202216581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34560, while the sum is 38.

The spelling of 1361202216581 in words is "one trillion, three hundred sixty-one billion, two hundred two million, two hundred sixteen thousand, five hundred eighty-one".