145561 has 4 divisors (see below), whose sum is σ = 156772. Its totient is φ = 134352.

The previous prime is 145549. The next prime is 145577. The reversal of 145561 is 165541.

145561 is nontrivially palindromic in base 11.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 27225 + 118336 = 165^2 + 344^2 .

It is a cyclic number.

It is not a de Polignac number, because 145561 - 2⁷ = 145433 is a prime.

It is a Duffinian number.

145561 is a lucky number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (145501) 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, 5586 + ... + 5611.

It is an arithmetic number, because the mean of its divisors is an integer number (39193).

2¹⁴⁵⁵⁶¹ is an apocalyptic number.

It is an amenable number.

145561 is a deficient number, since it is larger than the sum of its proper divisors (11211).

145561 is a wasteful number, since it uses less digits than its factorization.

145561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11210.

The product of its digits is 600, while the sum is 22.

The square root of 145561 is about 381.5245732584. The cubic root of 145561 is about 52.6035447018.

The spelling of 145561 in words is "one hundred forty-five thousand, five hundred sixty-one".