1609791409 has 2 divisors, whose sum is σ = 1609791410. Its totient is φ = 1609791408.

The previous prime is 1609791377. The next prime is 1609791427. The reversal of 1609791409 is 9041979061.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 877818384 + 731973025 = 29628^2 + 27055^2 .

It is an emirp because it is prime and its reverse (9041979061) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1609791409 - 2⁵ = 1609791377 is a prime.

It is not a weakly prime, because it can be changed into another prime (1609791439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 804895704 + 804895705.

It is an arithmetic number, because the mean of its divisors is an integer number (804895705).

Almost surely, 2^1609791409 is an apocalyptic number.

It is an amenable number.

1609791409 is a deficient number, since it is larger than the sum of its proper divisors (1).

1609791409 is an equidigital number, since it uses as much as digits as its factorization.

1609791409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 122472, while the sum is 46.

The square root of 1609791409 is about 40122.2059338716. The cubic root of 1609791409 is about 1171.9880993814.

The spelling of 1609791409 in words is "one billion, six hundred nine million, seven hundred ninety-one thousand, four hundred nine".