6540663 has 4 divisors (see below), whose sum is σ = 8720888. Its totient is φ = 4360440.

The previous prime is 6540643. The next prime is 6540673. The reversal of 6540663 is 3660456.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 6540663 - 2⁸ = 6540407 is a prime.

It is an Ulam number.

It is a D-number.

It is a Duffinian number.

6540663 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 6540663.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6540623) 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, 1090108 + ... + 1090113.

It is an arithmetic number, because the mean of its divisors is an integer number (2180222).

Almost surely, 2^6540663 is an apocalyptic number.

6540663 is a deficient number, since it is larger than the sum of its proper divisors (2180225).

6540663 is a wasteful number, since it uses less digits than its factorization.

6540663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2180224.

The product of its (nonzero) digits is 12960, while the sum is 30.

The square root of 6540663 is about 2557.4719939816. The cubic root of 6540663 is about 187.0139160528.

The spelling of 6540663 in words is "six million, five hundred forty thousand, six hundred sixty-three".