540721 has 8 divisors (see below), whose sum is σ = 576000. Its totient is φ = 506160.

The previous prime is 540713. The next prime is 540751. The reversal of 540721 is 127045.

540721 = 4² + 5² + ... + 117².

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 540721 - 2³ = 540713 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a Duffinian number.

It is a nialpdrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (540751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2736 + ... + 2926.

It is an arithmetic number, because the mean of its divisors is an integer number (72000).

2⁵⁴⁰⁷²¹ is an apocalyptic number.

It is an amenable number.

540721 is a deficient number, since it is larger than the sum of its proper divisors (35279).

540721 is a wasteful number, since it uses less digits than its factorization.

540721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 359.

The product of its (nonzero) digits is 280, while the sum is 19.

The square root of 540721 is about 735.3373375533. The cubic root of 540721 is about 81.4687548815.

Adding to 540721 its reverse (127045), we get a palindrome (667766).

The spelling of 540721 in words is "five hundred forty thousand, seven hundred twenty-one".