161577917 has 2 divisors, whose sum is σ = 161577918. Its totient is φ = 161577916.

The previous prime is 161577907. The next prime is 161577929. The reversal of 161577917 is 719775161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 157226521 + 4351396 = 12539^2 + 2086^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161577917 is a prime.

It is a super-2 number, since 2×161577917² = 52214846524117778, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161577907) 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, 80788958 + 80788959.

It is an arithmetic number, because the mean of its divisors is an integer number (80788959).

Almost surely, 2^161577917 is an apocalyptic number.

It is an amenable number.

161577917 is a deficient number, since it is larger than the sum of its proper divisors (1).

161577917 is an equidigital number, since it uses as much as digits as its factorization.

161577917 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 92610, while the sum is 44.

The square root of 161577917 is about 12711.3302608342. The cubic root of 161577917 is about 544.6623242800.

The spelling of 161577917 in words is "one hundred sixty-one million, five hundred seventy-seven thousand, nine hundred seventeen".