6511891 has 8 divisors (see below), whose sum is σ = 6809600. Its totient is φ = 6219720.

The previous prime is 6511871. The next prime is 6511909. The reversal of 6511891 is 1981156.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6511891 - 2¹¹ = 6509843 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6511801) 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, 1120 + ... + 3778.

It is an arithmetic number, because the mean of its divisors is an integer number (851200).

Almost surely, 2^6511891 is an apocalyptic number.

6511891 is a deficient number, since it is larger than the sum of its proper divisors (297709).

6511891 is a wasteful number, since it uses less digits than its factorization.

6511891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2769.

The product of its digits is 2160, while the sum is 31.

The square root of 6511891 is about 2551.8407081948. The cubic root of 6511891 is about 186.7392918227.

The spelling of 6511891 in words is "six million, five hundred eleven thousand, eight hundred ninety-one".