545981 has 4 divisors (see below), whose sum is σ = 551100. Its totient is φ = 540864.

The previous prime is 545959. The next prime is 546001. The reversal of 545981 is 189545.

545981 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.

It can be written as a sum of positive squares in 2 ways, for example, as 320356 + 225625 = 566^2 + 475^2 .

It is a cyclic number.

It is not a de Polignac number, because 545981 - 2⁶ = 545917 is a prime.

It is a super-2 number, since 2×545981² = 596190504722, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

545981 is a modest number, since divided by 981 gives 545 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (545911) 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, 2396 + ... + 2613.

It is an arithmetic number, because the mean of its divisors is an integer number (137775).

2⁵⁴⁵⁹⁸¹ is an apocalyptic number.

It is an amenable number.

545981 is a deficient number, since it is larger than the sum of its proper divisors (5119).

545981 is a wasteful number, since it uses less digits than its factorization.

545981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5118.

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

The square root of 545981 is about 738.9052713305. The cubic root of 545981 is about 81.7320721815.

The spelling of 545981 in words is "five hundred forty-five thousand, nine hundred eighty-one".