1691543179841 has 2 divisors, whose sum is σ = 1691543179842. Its totient is φ = 1691543179840.

The previous prime is 1691543179819. The next prime is 1691543179861. The reversal of 1691543179841 is 1489713451961.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1210871356816 + 480671823025 = 1100396^2 + 693305^2 .

It is a cyclic number.

It is not a de Polignac number, because 1691543179841 - 2¹⁸ = 1691542917697 is a prime.

It is a super-2 number, since 2×1691543179841² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1691543179861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 845771589920 + 845771589921.

It is an arithmetic number, because the mean of its divisors is an integer number (845771589921).

Almost surely, 2^{1691543179841} is an apocalyptic number.

It is an amenable number.

1691543179841 is a deficient number, since it is larger than the sum of its proper divisors (1).

1691543179841 is an equidigital number, since it uses as much as digits as its factorization.

1691543179841 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6531840, while the sum is 59.

The spelling of 1691543179841 in words is "one trillion, six hundred ninety-one billion, five hundred forty-three million, one hundred seventy-nine thousand, eight hundred forty-one".