161961508 has 24 divisors (see below), whose sum is σ = 288368640. Its totient is φ = 79578240.

The previous prime is 161961497. The next prime is 161961509. The reversal of 161961508 is 805169161.

It is not an unprimeable number, because it can be changed into a prime (161961509) 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 in 7 ways as a sum of consecutive naturals, for example, 108028 + ... + 109516.

It is an arithmetic number, because the mean of its divisors is an integer number (12015360).

Almost surely, 2^161961508 is an apocalyptic number.

It is an amenable number.

161961508 is a deficient number, since it is larger than the sum of its proper divisors (126407132).

161961508 is a wasteful number, since it uses less digits than its factorization.

161961508 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1947 (or 1945 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 37.

The square root of 161961508 is about 12726.4098629582. The cubic root of 161961508 is about 545.0929987470.

The spelling of 161961508 in words is "one hundred sixty-one million, nine hundred sixty-one thousand, five hundred eight".