161285231 has 4 divisors (see below), whose sum is σ = 161568264. Its totient is φ = 161002200.

The previous prime is 161285227. The next prime is 161285237. The reversal of 161285231 is 132582161.

161285231 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 132582161 = 137 ⋅967753.

It is a cyclic number.

It is not a de Polignac number, because 161285231 - 2² = 161285227 is a prime.

It is a super-2 number, since 2×161285231² = 52025851477446722, 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 = 161285194 and 161285203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161285237) 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, 140660 + ... + 141801.

It is an arithmetic number, because the mean of its divisors is an integer number (40392066).

Almost surely, 2^161285231 is an apocalyptic number.

161285231 is a deficient number, since it is larger than the sum of its proper divisors (283033).

161285231 is an equidigital number, since it uses as much as digits as its factorization.

161285231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283032.

The product of its digits is 2880, while the sum is 29.

The square root of 161285231 is about 12699.8122427066. The cubic root of 161285231 is about 544.3332541673. Note that the first 3 decimals are identical.

The spelling of 161285231 in words is "one hundred sixty-one million, two hundred eighty-five thousand, two hundred thirty-one".