540691 has 2 divisors, whose sum is σ = 540692. Its totient is φ = 540690.

The previous prime is 540689. The next prime is 540697. The reversal of 540691 is 196045.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 540691 - 2¹ = 540689 is a prime.

Together with 540689, it forms a pair of twin primes.

540691 is a lucky number.

It is a nialpdrome in base 15.

It is not a weakly prime, because it can be changed into another prime (540697) 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 as a sum of consecutive naturals, namely, 270345 + 270346.

It is an arithmetic number, because the mean of its divisors is an integer number (270346).

2⁵⁴⁰⁶⁹¹ is an apocalyptic number.

540691 is a deficient number, since it is larger than the sum of its proper divisors (1).

540691 is an equidigital number, since it uses as much as digits as its factorization.

540691 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 540691 is about 735.3169384694. The cubic root of 540691 is about 81.4672481847.

The spelling of 540691 in words is "five hundred forty thousand, six hundred ninety-one".