1609381559 has 4 divisors (see below), whose sum is σ = 1611620640. Its totient is φ = 1607142480.

The previous prime is 1609381549. The next prime is 1609381573. The reversal of 1609381559 is 9551839061.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9551839061 = 137 ⋅69721453.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1609381559 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1609381519) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1118462 + ... + 1119899.

It is an arithmetic number, because the mean of its divisors is an integer number (402905160).

Almost surely, 2^1609381559 is an apocalyptic number.

1609381559 is a deficient number, since it is larger than the sum of its proper divisors (2239081).

1609381559 is an equidigital number, since it uses as much as digits as its factorization.

1609381559 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2239080.

The product of its (nonzero) digits is 291600, while the sum is 47.

The square root of 1609381559 is about 40117.0980879724. The cubic root of 1609381559 is about 1171.8886289179. Note that the first 3 decimals are identical.

The spelling of 1609381559 in words is "one billion, six hundred nine million, three hundred eighty-one thousand, five hundred fifty-nine".