545891 has 4 divisors (see below), whose sum is σ = 552552. Its totient is φ = 539232.

The previous prime is 545873. The next prime is 545893. The reversal of 545891 is 198545.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 198545 = 5 ⋅39709.

It is a cyclic number.

It is not a de Polignac number, because 545891 - 2⁶ = 545827 is a prime.

It is a Duffinian number.

It is a plaindrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (545893) 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, 3206 + ... + 3371.

It is an arithmetic number, because the mean of its divisors is an integer number (138138).

2⁵⁴⁵⁸⁹¹ is an apocalyptic number.

545891 is a deficient number, since it is larger than the sum of its proper divisors (6661).

545891 is an equidigital number, since it uses as much as digits as its factorization.

545891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6660.

The product of its digits is 7200, while the sum is 32.

The square root of 545891 is about 738.8443679152. The cubic root of 545891 is about 81.7275810053.

The spelling of 545891 in words is "five hundred forty-five thousand, eight hundred ninety-one".