145581 has 4 divisors (see below), whose sum is σ = 194112. Its totient is φ = 97052.

The previous prime is 145577. The next prime is 145589. The reversal of 145581 is 185541.

145581 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 a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 145581 - 2² = 145577 is a prime.

It is a super-2 number, since 2×145581² = 42387655122, which contains 22 as substring.

It is a D-number.

It is a plaindrome in base 16.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 145581.

It is not an unprimeable number, because it can be changed into a prime (145589) 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, 24261 + ... + 24266.

It is an arithmetic number, because the mean of its divisors is an integer number (48528).

2¹⁴⁵⁵⁸¹ is an apocalyptic number.

It is an amenable number.

145581 is a deficient number, since it is larger than the sum of its proper divisors (48531).

145581 is an equidigital number, since it uses as much as digits as its factorization.

145581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48530.

The product of its digits is 800, while the sum is 24.

The square root of 145581 is about 381.5507829896. The cubic root of 145581 is about 52.6059538240.

It can be divided in two parts, 1455 and 81, that multiplied together give a triangular number (117855 = T₄₈₅).

The spelling of 145581 in words is "one hundred forty-five thousand, five hundred eighty-one".