161431836 has 24 divisors (see below), whose sum is σ = 378856464. Its totient is φ = 53498880.

The previous prime is 161431817. The next prime is 161431841. The reversal of 161431836 is 638134161.

It is a junction number, because it is equal to n+sod(n) for n = 161431797 and 161431806.

It is a congruent 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 7 ways as a sum of consecutive naturals, for example, 36805 + ... + 40956.

It is an arithmetic number, because the mean of its divisors is an integer number (15785686).

Almost surely, 2^161431836 is an apocalyptic number.

It is an amenable number.

161431836 is an abundant number, since it is smaller than the sum of its proper divisors (217424628).

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

161431836 is a wasteful number, since it uses less digits than its factorization.

161431836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77941 (or 77939 counting only the distinct ones).

The product of its digits is 10368, while the sum is 33.

The square root of 161431836 is about 12705.5828673855. The cubic root of 161431836 is about 544.4981335118.

Adding to 161431836 its reverse (638134161), we get a palindrome (799565997).

The spelling of 161431836 in words is "one hundred sixty-one million, four hundred thirty-one thousand, eight hundred thirty-six".