161457209 has 2 divisors, whose sum is σ = 161457210. Its totient is φ = 161457208.

The previous prime is 161457187. The next prime is 161457251. The reversal of 161457209 is 902754161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 130599184 + 30858025 = 11428^2 + 5555^2 .

It is a cyclic number.

It is not a de Polignac number, because 161457209 - 2¹² = 161453113 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (161457299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80728604 + 80728605.

It is an arithmetic number, because the mean of its divisors is an integer number (80728605).

Almost surely, 2^161457209 is an apocalyptic number.

It is an amenable number.

161457209 is a deficient number, since it is larger than the sum of its proper divisors (1).

161457209 is an equidigital number, since it uses as much as digits as its factorization.

161457209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 161457209 is about 12706.5813262262. The cubic root of 161457209 is about 544.5266591271.

The spelling of 161457209 in words is "one hundred sixty-one million, four hundred fifty-seven thousand, two hundred nine".