161677909 has 2 divisors, whose sum is σ = 161677910. Its totient is φ = 161677908.

The previous prime is 161677889. The next prime is 161677913. The reversal of 161677909 is 909776161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 105472900 + 56205009 = 10270^2 + 7497^2 .

It is a cyclic number.

It is not a de Polignac number, because 161677909 - 2¹¹ = 161675861 is a prime.

It is a super-2 number, since 2×161677909² = 52279492517224562, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161677949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80838954 + 80838955.

It is an arithmetic number, because the mean of its divisors is an integer number (80838955).

Almost surely, 2^161677909 is an apocalyptic number.

It is an amenable number.

161677909 is a deficient number, since it is larger than the sum of its proper divisors (1).

161677909 is an equidigital number, since it uses as much as digits as its factorization.

161677909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 142884, while the sum is 46.

The square root of 161677909 is about 12715.2628364497. The cubic root of 161677909 is about 544.7746553161.

The spelling of 161677909 in words is "one hundred sixty-one million, six hundred seventy-seven thousand, nine hundred nine".