161667109 has 2 divisors, whose sum is σ = 161667110. Its totient is φ = 161667108.

The previous prime is 161667073. The next prime is 161667113. The reversal of 161667109 is 901766161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 111894084 + 49773025 = 10578^2 + 7055^2 .

It is a cyclic number.

It is not a de Polignac number, because 161667109 - 2¹¹ = 161665061 is a prime.

It is a super-2 number, since 2×161667109² = 52272508264835762, 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 (161665109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80833554 + 80833555.

It is an arithmetic number, because the mean of its divisors is an integer number (80833555).

Almost surely, 2^161667109 is an apocalyptic number.

It is an amenable number.

161667109 is a deficient number, since it is larger than the sum of its proper divisors (1).

161667109 is an equidigital number, since it uses as much as digits as its factorization.

161667109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13608, while the sum is 37.

The square root of 161667109 is about 12714.8381428943. The cubic root of 161667109 is about 544.7625248250.

The spelling of 161667109 in words is "one hundred sixty-one million, six hundred sixty-seven thousand, one hundred nine".