161661612341 has 2 divisors, whose sum is σ = 161661612342. Its totient is φ = 161661612340.

The previous prime is 161661612283. The next prime is 161661612373. The reversal of 161661612341 is 143216166161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 121121400625 + 40540211716 = 348025^2 + 201346^2 .

It is an emirp because it is prime and its reverse (143216166161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 161661612341 - 2¹⁰ = 161661611317 is a prime.

It is a super-2 number, since 2×161661612341² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 161661612295 and 161661612304.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161661615341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80830806170 + 80830806171.

It is an arithmetic number, because the mean of its divisors is an integer number (80830806171).

Almost surely, 2^161661612341 is an apocalyptic number.

It is an amenable number.

161661612341 is a deficient number, since it is larger than the sum of its proper divisors (1).

161661612341 is an equidigital number, since it uses as much as digits as its factorization.

161661612341 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 38.

The spelling of 161661612341 in words is "one hundred sixty-one billion, six hundred sixty-one million, six hundred twelve thousand, three hundred forty-one".