161322831 has 12 divisors (see below), whose sum is σ = 237419208. Its totient is φ = 105519024.

The previous prime is 161322829. The next prime is 161322839. The reversal of 161322831 is 138223161.

It is a happy number.

It is not a de Polignac number, because 161322831 - 2¹ = 161322829 is a prime.

It is a super-2 number, since 2×161322831² = 52050111603709122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 161322795 and 161322804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161322839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 168625 + ... + 169578.

It is an arithmetic number, because the mean of its divisors is an integer number (19784934).

Almost surely, 2^161322831 is an apocalyptic number.

161322831 is a deficient number, since it is larger than the sum of its proper divisors (76096377).

161322831 is a wasteful number, since it uses less digits than its factorization.

161322831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 338262 (or 338259 counting only the distinct ones).

The product of its digits is 1728, while the sum is 27.

The square root of 161322831 is about 12701.2924932859. The cubic root of 161322831 is about 544.3755505387.

Adding to 161322831 its reverse (138223161), we get a palindrome (299545992).

The spelling of 161322831 in words is "one hundred sixty-one million, three hundred twenty-two thousand, eight hundred thirty-one".