161556365417 has 2 divisors, whose sum is σ = 161556365418. Its totient is φ = 161556365416.

The previous prime is 161556365407. The next prime is 161556365459. The reversal of 161556365417 is 714563655161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 107860353241 + 53696012176 = 328421^2 + 231724^2 .

It is a cyclic number.

It is not a de Polignac number, because 161556365417 - 2⁴ = 161556365401 is a prime.

It is a super-2 number, since 2×161556365417² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (161556365407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80778182708 + 80778182709.

It is an arithmetic number, because the mean of its divisors is an integer number (80778182709).

Almost surely, 2^161556365417 is an apocalyptic number.

It is an amenable number.

161556365417 is a deficient number, since it is larger than the sum of its proper divisors (1).

161556365417 is an equidigital number, since it uses as much as digits as its factorization.

161556365417 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2268000, while the sum is 50.

The spelling of 161556365417 in words is "one hundred sixty-one billion, five hundred fifty-six million, three hundred sixty-five thousand, four hundred seventeen".