161207142181 has 2 divisors, whose sum is σ = 161207142182. Its totient is φ = 161207142180.

The previous prime is 161207142149. The next prime is 161207142293. The reversal of 161207142181 is 181241702161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 138659416900 + 22547725281 = 372370^2 + 150159^2 .

It is a cyclic number.

It is not a de Polignac number, because 161207142181 - 2⁵ = 161207142149 is a prime.

It is a super-2 number, since 2×161207142181² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161207142781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80603571090 + 80603571091.

It is an arithmetic number, because the mean of its divisors is an integer number (80603571091).

Almost surely, 2^161207142181 is an apocalyptic number.

It is an amenable number.

161207142181 is a deficient number, since it is larger than the sum of its proper divisors (1).

161207142181 is an equidigital number, since it uses as much as digits as its factorization.

161207142181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5376, while the sum is 34.

The spelling of 161207142181 in words is "one hundred sixty-one billion, two hundred seven million, one hundred forty-two thousand, one hundred eighty-one".