16021609 has 2 divisors, whose sum is σ = 16021610. Its totient is φ = 16021608.

The previous prime is 16021597. The next prime is 16021613. The reversal of 16021609 is 90612061.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16000000 + 21609 = 4000^2 + 147^2 .

It is an emirp because it is prime and its reverse (90612061) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16021609 - 2⁹ = 16021097 is a prime.

It is not a weakly prime, because it can be changed into another prime (16021669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8010804 + 8010805.

It is an arithmetic number, because the mean of its divisors is an integer number (8010805).

Almost surely, 2^16021609 is an apocalyptic number.

It is an amenable number.

16021609 is a deficient number, since it is larger than the sum of its proper divisors (1).

16021609 is an equidigital number, since it uses as much as digits as its factorization.

16021609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 16021609 is about 4002.7002136058. The cubic root of 16021609 is about 252.0975990895.

The spelling of 16021609 in words is "sixteen million, twenty-one thousand, six hundred nine".