161798538 has 24 divisors (see below), whose sum is σ = 355690944. Its totient is φ = 49029640.

The previous prime is 161798531. The next prime is 161798561. The reversal of 161798538 is 835897161.

It is not an unprimeable number, because it can be changed into a prime (161798531) 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 11 ways as a sum of consecutive naturals, for example, 110706 + ... + 112157.

It is an arithmetic number, because the mean of its divisors is an integer number (14820456).

Almost surely, 2^161798538 is an apocalyptic number.

161798538 is an abundant number, since it is smaller than the sum of its proper divisors (193892406).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161798538 is a wasteful number, since it uses less digits than its factorization.

161798538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222890 (or 222879 counting only the distinct ones).

The product of its digits is 362880, while the sum is 48.

The square root of 161798538 is about 12720.0054245271. The cubic root of 161798538 is about 544.9101083400.

The spelling of 161798538 in words is "one hundred sixty-one million, seven hundred ninety-eight thousand, five hundred thirty-eight".