161555117 has 2 divisors, whose sum is σ = 161555118. Its totient is φ = 161555116.

The previous prime is 161555111. The next prime is 161555123. The reversal of 161555117 is 711555161.

It is a balanced prime because it is at equal distance from previous prime (161555111) and next prime (161555123).

It can be written as a sum of positive squares in only one way, i.e., 123965956 + 37589161 = 11134^2 + 6131^2 .

It is a cyclic number.

It is not a de Polignac number, because 161555117 - 2¹² = 161551021 is a prime.

It is a super-2 number, since 2×161555117² = 52200111657767378, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161555111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80777558 + 80777559.

It is an arithmetic number, because the mean of its divisors is an integer number (80777559).

Almost surely, 2^161555117 is an apocalyptic number.

It is an amenable number.

161555117 is a deficient number, since it is larger than the sum of its proper divisors (1).

161555117 is an equidigital number, since it uses as much as digits as its factorization.

161555117 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5250, while the sum is 32.

The square root of 161555117 is about 12710.4333915095. The cubic root of 161555117 is about 544.6367042667.

The spelling of 161555117 in words is "one hundred sixty-one million, five hundred fifty-five thousand, one hundred seventeen".