540409 has 4 divisors (see below), whose sum is σ = 542080. Its totient is φ = 538740.

The previous prime is 540391. The next prime is 540433. The reversal of 540409 is 904045.

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 540409 - 2⁵ = 540377 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 540409.

It is not an unprimeable number, because it can be changed into a prime (540469) 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, 177 + ... + 1054.

It is an arithmetic number, because the mean of its divisors is an integer number (135520).

2⁵⁴⁰⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

540409 is a deficient number, since it is larger than the sum of its proper divisors (1671).

540409 is a wasteful number, since it uses less digits than its factorization.

540409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1670.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 540409 is about 735.1251594116. The cubic root of 540409 is about 81.4530825096.

It can be divided in two parts, 540 and 409, that added together give a palindrome (949).

The spelling of 540409 in words is "five hundred forty thousand, four hundred nine".