161871277 has 2 divisors, whose sum is σ = 161871278. Its totient is φ = 161871276.

The previous prime is 161871253. The next prime is 161871287. The reversal of 161871277 is 772178161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 87721956 + 74149321 = 9366^2 + 8611^2 .

It is a cyclic number.

It is not a de Polignac number, because 161871277 - 2¹⁹ = 161346989 is a prime.

It is a super-2 number, since 2×161871277² = 52404620635221458, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161871287) 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, 80935638 + 80935639.

It is an arithmetic number, because the mean of its divisors is an integer number (80935639).

Almost surely, 2^161871277 is an apocalyptic number.

It is an amenable number.

161871277 is a deficient number, since it is larger than the sum of its proper divisors (1).

161871277 is an equidigital number, since it uses as much as digits as its factorization.

161871277 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32928, while the sum is 40.

The square root of 161871277 is about 12722.8643394481. The cubic root of 161871277 is about 544.9917536558.

The spelling of 161871277 in words is "one hundred sixty-one million, eight hundred seventy-one thousand, two hundred seventy-seven".