161553 has 16 divisors (see below), whose sum is σ = 252800. Its totient is φ = 91728.

The previous prime is 161543. The next prime is 161561. The reversal of 161553 is 355161.

It is a happy number.

161553 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 161553 - 2⁵ = 161521 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161503) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 951 + ... + 1107.

It is an arithmetic number, because the mean of its divisors is an integer number (15800).

2¹⁶¹⁵⁵³ is an apocalyptic number.

It is an amenable number.

161553 is a deficient number, since it is larger than the sum of its proper divisors (91247).

161553 is an equidigital number, since it uses as much as digits as its factorization.

161553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181 (or 167 counting only the distinct ones).

The product of its digits is 450, while the sum is 21.

The square root of 161553 is about 401.9365621588. The cubic root of 161553 is about 54.4634325304.

The spelling of 161553 in words is "one hundred sixty-one thousand, five hundred fifty-three".