161404231 has 4 divisors (see below), whose sum is σ = 164050264. Its totient is φ = 158758200.

The previous prime is 161404223. The next prime is 161404253. The reversal of 161404231 is 132404161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 132404161 = 499 ⋅265339.

It is a cyclic number.

It is not a de Polignac number, because 161404231 - 2³ = 161404223 is a prime.

It is a super-2 number, since 2×161404231² = 52102651569402722, 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 (161404261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1322925 + ... + 1323046.

It is an arithmetic number, because the mean of its divisors is an integer number (41012566).

Almost surely, 2^161404231 is an apocalyptic number.

161404231 is a deficient number, since it is larger than the sum of its proper divisors (2646033).

161404231 is an equidigital number, since it uses as much as digits as its factorization.

161404231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2646032.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 161404231 is about 12704.4964874646. The cubic root of 161404231 is about 544.4670951735.

Adding to 161404231 its reverse (132404161), we get a palindrome (293808392).

The spelling of 161404231 in words is "one hundred sixty-one million, four hundred four thousand, two hundred thirty-one".