161605508 has 6 divisors (see below), whose sum is σ = 282809646. Its totient is φ = 80802752.

The previous prime is 161605501. The next prime is 161605513. The reversal of 161605508 is 805506161.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 89151364 + 72454144 = 9442^2 + 8512^2 .

It is a super-2 number, since 2×161605508² = 52232680431876128, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161605501) 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, 20200685 + ... + 20200692.

It is an arithmetic number, because the mean of its divisors is an integer number (47134941).

Almost surely, 2^161605508 is an apocalyptic number.

It is an amenable number.

161605508 is a deficient number, since it is larger than the sum of its proper divisors (121204138).

161605508 is a wasteful number, since it uses less digits than its factorization.

161605508 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40401381 (or 40401379 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 32.

The square root of 161605508 is about 12712.4155061106. The cubic root of 161605508 is about 544.6933246443.

The spelling of 161605508 in words is "one hundred sixty-one million, six hundred five thousand, five hundred eight".