161340831 has 24 divisors (see below), whose sum is σ = 242415680. Its totient is φ = 103311936.

The previous prime is 161340821. The next prime is 161340857. The reversal of 161340831 is 138043161.

161340831 is a `hidden beast` number, since 1 + 613 + 40 + 8 + 3 + 1 = 666.

It is not a de Polignac number, because 161340831 - 2¹¹ = 161338783 is a prime.

It is a super-2 number, since 2×161340831² = 52061727495541122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 161340795 and 161340804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161340811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23241 + ... + 29373.

Almost surely, 2^161340831 is an apocalyptic number.

161340831 is a deficient number, since it is larger than the sum of its proper divisors (81074849).

161340831 is a wasteful number, since it uses less digits than its factorization.

161340831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6255 (or 6252 counting only the distinct ones).

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

The square root of 161340831 is about 12702.0010628247. The cubic root of 161340831 is about 544.3957964755.

Subtracting from 161340831 its sum of digits (27), we obtain a square (161340804 = 12702²).

Adding to 161340831 its reverse (138043161), we get a palindrome (299383992).

The spelling of 161340831 in words is "one hundred sixty-one million, three hundred forty thousand, eight hundred thirty-one".