6540644 has 24 divisors (see below), whose sum is σ = 12780768. Its totient is φ = 2903040.

The previous prime is 6540643. The next prime is 6540673. The reversal of 6540644 is 4460456.

It is not an unprimeable number, because it can be changed into a prime (6540643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 164 + ... + 3620.

It is an arithmetic number, because the mean of its divisors is an integer number (532532).

Almost surely, 2^6540644 is an apocalyptic number.

It is an amenable number.

6540644 is a deficient number, since it is larger than the sum of its proper divisors (6240124).

6540644 is a wasteful number, since it uses less digits than its factorization.

6540644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3515 (or 3513 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 29.

The square root of 6540644 is about 2557.4682793732. The cubic root of 6540644 is about 187.0137349668.

The spelling of 6540644 in words is "six million, five hundred forty thousand, six hundred forty-four".