161271217 has 2 divisors, whose sum is σ = 161271218. Its totient is φ = 161271216.

The previous prime is 161271203. The next prime is 161271223. The reversal of 161271217 is 712172161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 117592336 + 43678881 = 10844^2 + 6609^2 .

It is a cyclic number.

It is not a de Polignac number, because 161271217 - 2²⁷ = 27053489 is a prime.

It is a super-2 number, since 2×161271217² = 52016810865322178, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (161271917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80635608 + 80635609.

It is an arithmetic number, because the mean of its divisors is an integer number (80635609).

Almost surely, 2^161271217 is an apocalyptic number.

It is an amenable number.

161271217 is a deficient number, since it is larger than the sum of its proper divisors (1).

161271217 is an equidigital number, since it uses as much as digits as its factorization.

161271217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1176, while the sum is 28.

The square root of 161271217 is about 12699.2604902805. The cubic root of 161271217 is about 544.3174880881.

The spelling of 161271217 in words is "one hundred sixty-one million, two hundred seventy-one thousand, two hundred seventeen".