145891 has 4 divisors (see below), whose sum is σ = 149872. Its totient is φ = 141912.

The previous prime is 145879. The next prime is 145897. The reversal of 145891 is 198541.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 145891 - 2¹³ = 137699 is a prime.

It is a Duffinian number.

145891 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (145897) 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, 1935 + ... + 2008.

It is an arithmetic number, because the mean of its divisors is an integer number (37468).

2¹⁴⁵⁸⁹¹ is an apocalyptic number.

145891 is a deficient number, since it is larger than the sum of its proper divisors (3981).

145891 is an equidigital number, since it uses as much as digits as its factorization.

145891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3980.

The product of its digits is 1440, while the sum is 28.

The square root of 145891 is about 381.9568038404. The cubic root of 145891 is about 52.6432670358.

Subtracting 145891 from its reverse (198541), we obtain a triangular number (52650 = T₃₂₄).

The spelling of 145891 in words is "one hundred forty-five thousand, eight hundred ninety-one".