161431 has 4 divisors (see below), whose sum is σ = 165832. Its totient is φ = 157032.

The previous prime is 161411. The next prime is 161453. The reversal of 161431 is 134161.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 161431 - 2⁷ = 161303 is a prime.

It is a super-2 number, since 2×161431² = 52119935522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2145 + ... + 2218.

It is an arithmetic number, because the mean of its divisors is an integer number (41458).

2¹⁶¹⁴³¹ is an apocalyptic number.

161431 is a deficient number, since it is larger than the sum of its proper divisors (4401).

161431 is an equidigital number, since it uses as much as digits as its factorization.

161431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4400.

The product of its digits is 72, while the sum is 16.

The square root of 161431 is about 401.7847682529. The cubic root of 161431 is about 54.4497193587.

Adding to 161431 its reverse (134161), we get a palindrome (295592).

The spelling of 161431 in words is "one hundred sixty-one thousand, four hundred thirty-one".