6561111 has 4 divisors (see below), whose sum is σ = 8748152. Its totient is φ = 4374072.

The previous prime is 6561103. The next prime is 6561127. The reversal of 6561111 is 1111656.

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

It is not a de Polignac number, because 6561111 - 2³ = 6561103 is a prime.

It is a D-number.

It is a Duffinian number.

6561111 is a modest number, since divided by 1111 gives 656 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6561151) 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, 1093516 + ... + 1093521.

It is an arithmetic number, because the mean of its divisors is an integer number (2187038).

Almost surely, 2^6561111 is an apocalyptic number.

6561111 is a deficient number, since it is larger than the sum of its proper divisors (2187041).

6561111 is a wasteful number, since it uses less digits than its factorization.

6561111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2187040.

The product of its digits is 180, while the sum is 21.

The square root of 6561111 is about 2561.4665721028. The cubic root of 6561111 is about 187.2085998040.

Adding to 6561111 its reverse (1111656), we get a palindrome (7672767).

The spelling of 6561111 in words is "six million, five hundred sixty-one thousand, one hundred eleven".