540686561 has 4 divisors (see below), whose sum is σ = 549850800. Its totient is φ = 531522324.

The previous prime is 540686537. The next prime is 540686563. The reversal of 540686561 is 165686045.

It is a happy number.

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 540686561 - 2²⁶ = 473577697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (540686563) 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, 4582031 + ... + 4582148.

It is an arithmetic number, because the mean of its divisors is an integer number (137462700).

Almost surely, 2^540686561 is an apocalyptic number.

It is an amenable number.

540686561 is a deficient number, since it is larger than the sum of its proper divisors (9164239).

540686561 is an equidigital number, since it uses as much as digits as its factorization.

540686561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9164238.

The product of its (nonzero) digits is 172800, while the sum is 41.

The square root of 540686561 is about 23252.6678254346. The cubic root of 540686561 is about 814.6702523906.

The spelling of 540686561 in words is "five hundred forty million, six hundred eighty-six thousand, five hundred sixty-one".