161831018 has 32 divisors (see below), whose sum is σ = 263450880. Its totient is φ = 74304000.

The previous prime is 161831009. The next prime is 161831023. The reversal of 161831018 is 810138161.

It is a Curzon number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 375263 + ... + 375693.

It is an arithmetic number, because the mean of its divisors is an integer number (8232840).

Almost surely, 2^161831018 is an apocalyptic number.

161831018 is a deficient number, since it is larger than the sum of its proper divisors (101619862).

161831018 is a wasteful number, since it uses less digits than its factorization.

161831018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 734.

The product of its (nonzero) digits is 1152, while the sum is 29.

The square root of 161831018 is about 12721.2820894751. The cubic root of 161831018 is about 544.9465682825.

Adding to 161831018 its reverse (810138161), we get a palindrome (971969179).

The spelling of 161831018 in words is "one hundred sixty-one million, eight hundred thirty-one thousand, eighteen".