6541649 has 4 divisors (see below), whose sum is σ = 6579636. Its totient is φ = 6503664.

The previous prime is 6541621. The next prime is 6541663. The reversal of 6541649 is 9461456.

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

It can be written as a sum of positive squares in 2 ways, for example, as 2310400 + 4231249 = 1520^2 + 2057^2 .

It is a cyclic number.

It is not a de Polignac number, because 6541649 - 2⁸ = 6541393 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6541609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18734 + ... + 19079.

It is an arithmetic number, because the mean of its divisors is an integer number (1644909).

Almost surely, 2^6541649 is an apocalyptic number.

It is an amenable number.

6541649 is a deficient number, since it is larger than the sum of its proper divisors (37987).

6541649 is a wasteful number, since it uses less digits than its factorization.

6541649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37986.

The product of its digits is 25920, while the sum is 35.

The square root of 6541649 is about 2557.6647552015. The cubic root of 6541649 is about 187.0233129828.

It can be divided in two parts, 65 and 41649, that added together give a palindrome (41714).

The spelling of 6541649 in words is "six million, five hundred forty-one thousand, six hundred forty-nine".