1609608681 has 6 divisors (see below), whose sum is σ = 2324990330. Its totient is φ = 1073072448.

The previous prime is 1609608643. The next prime is 1609608683. The reversal of 1609608681 is 1868069061.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 1296000000 + 313608681 = 36000^2 + 17709^2 .

It is not a de Polignac number, because 1609608681 - 2¹⁷ = 1609477609 is a prime.

It is a super-2 number, since 2×1609608681² = 5181680211901119522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1609608683) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 89422696 + ... + 89422713.

Almost surely, 2^1609608681 is an apocalyptic number.

It is an amenable number.

1609608681 is a deficient number, since it is larger than the sum of its proper divisors (715381649).

1609608681 is a wasteful number, since it uses less digits than its factorization.

1609608681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178845415 (or 178845412 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The square root of 1609608681 is about 40119.9287262577. The cubic root of 1609608681 is about 1171.9437534403.

The spelling of 1609608681 in words is "one billion, six hundred nine million, six hundred eight thousand, six hundred eighty-one".