161662909 has 2 divisors, whose sum is σ = 161662910. Its totient is φ = 161662908.

The previous prime is 161662903. The next prime is 161662913. The reversal of 161662909 is 909266161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 160731684 + 931225 = 12678^2 + 965^2 .

It is an emirp because it is prime and its reverse (909266161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 161662909 - 2¹¹ = 161660861 is a prime.

It is a super-2 number, since 2×161662909² = 52269792292684562, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161662903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80831454 + 80831455.

It is an arithmetic number, because the mean of its divisors is an integer number (80831455).

Almost surely, 2^161662909 is an apocalyptic number.

It is an amenable number.

161662909 is a deficient number, since it is larger than the sum of its proper divisors (1).

161662909 is an equidigital number, since it uses as much as digits as its factorization.

161662909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34992, while the sum is 40.

The square root of 161662909 is about 12714.6729804584. The cubic root of 161662909 is about 544.7578072659.

The spelling of 161662909 in words is "one hundred sixty-one million, six hundred sixty-two thousand, nine hundred nine".