161533 has 4 divisors (see below), whose sum is σ = 162688. Its totient is φ = 160380.

The previous prime is 161531. The next prime is 161543. The reversal of 161533 is 335161.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 161533 - 2¹ = 161531 is a prime.

It is a Duffinian number.

161533 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 161533.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 333 + ... + 658.

It is an arithmetic number, because the mean of its divisors is an integer number (40672).

2¹⁶¹⁵³³ is an apocalyptic number.

It is an amenable number.

161533 is a deficient number, since it is larger than the sum of its proper divisors (1155).

161533 is an equidigital number, since it uses as much as digits as its factorization.

161533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1154.

The product of its digits is 270, while the sum is 19.

The square root of 161533 is about 401.9116818407. The cubic root of 161533 is about 54.4611849427.

Adding to 161533 its reverse (335161), we get a palindrome (496694).

The spelling of 161533 in words is "one hundred sixty-one thousand, five hundred thirty-three".