16509161 has 2 divisors, whose sum is σ = 16509162. Its totient is φ = 16509160.

The previous prime is 16509151. The next prime is 16509167. The reversal of 16509161 is 16190561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15366400 + 1142761 = 3920^2 + 1069^2 .

It is a cyclic number.

It is not a de Polignac number, because 16509161 - 2¹⁰ = 16508137 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (16509167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8254580 + 8254581.

It is an arithmetic number, because the mean of its divisors is an integer number (8254581).

Almost surely, 2^16509161 is an apocalyptic number.

It is an amenable number.

16509161 is a deficient number, since it is larger than the sum of its proper divisors (1).

16509161 is an equidigital number, since it uses as much as digits as its factorization.

16509161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1620, while the sum is 29.

The square root of 16509161 is about 4063.1466869903. The cubic root of 16509161 is about 254.6292754679.

The spelling of 16509161 in words is "sixteen million, five hundred nine thousand, one hundred sixty-one".