1967581243681 has 2 divisors, whose sum is σ = 1967581243682. Its totient is φ = 1967581243680.

The previous prime is 1967581243643. The next prime is 1967581243709. The reversal of 1967581243681 is 1863421857691.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1603629659025 + 363951584656 = 1266345^2 + 603284^2 .

It is an emirp because it is prime and its reverse (1863421857691) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1967581243681 is a prime.

It is a super-2 number, since 2×1967581243681² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1967581253681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 983790621840 + 983790621841.

It is an arithmetic number, because the mean of its divisors is an integer number (983790621841).

Almost surely, 2^{1967581243681} is an apocalyptic number.

It is an amenable number.

1967581243681 is a deficient number, since it is larger than the sum of its proper divisors (1).

1967581243681 is an equidigital number, since it uses as much as digits as its factorization.

1967581243681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17418240, while the sum is 61.

The spelling of 1967581243681 in words is "one trillion, nine hundred sixty-seven billion, five hundred eighty-one million, two hundred forty-three thousand, six hundred eighty-one".