6511643 has 4 divisors (see below), whose sum is σ = 6721728. Its totient is φ = 6301560.

The previous prime is 6511621. The next prime is 6511649. The reversal of 6511643 is 3461156.

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

It is a cyclic number.

It is not a de Polignac number, because 6511643 - 2⁸ = 6511387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6511649) 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, 104996 + ... + 105057.

It is an arithmetic number, because the mean of its divisors is an integer number (1680432).

Almost surely, 2^6511643 is an apocalyptic number.

6511643 is a deficient number, since it is larger than the sum of its proper divisors (210085).

6511643 is a wasteful number, since it uses less digits than its factorization.

6511643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210084.

The product of its digits is 2160, while the sum is 26.

The square root of 6511643 is about 2551.7921153574. The cubic root of 6511643 is about 186.7369211887.

Adding to 6511643 its reverse (3461156), we get a palindrome (9972799).

The spelling of 6511643 in words is "six million, five hundred eleven thousand, six hundred forty-three".