6561181 has 16 divisors (see below), whose sum is σ = 7520256. Its totient is φ = 5670000.

The previous prime is 6561161. The next prime is 6561193. The reversal of 6561181 is 1811656.

It is a cyclic number.

It is not a de Polignac number, because 6561181 - 2⁹ = 6560669 is a prime.

It is a super-2 number, since 2×6561181² = 86098192229522, which contains 22 as substring.

It is a Duffinian number.

6561181 is a lucky number.

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 15 ways as a sum of consecutive naturals, for example, 24076 + ... + 24346.

It is an arithmetic number, because the mean of its divisors is an integer number (470016).

Almost surely, 2^6561181 is an apocalyptic number.

It is an amenable number.

6561181 is a deficient number, since it is larger than the sum of its proper divisors (959075).

6561181 is a wasteful number, since it uses less digits than its factorization.

6561181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 384.

The product of its digits is 1440, while the sum is 28.

The square root of 6561181 is about 2561.4802361135. The cubic root of 6561181 is about 187.2092655731.

The spelling of 6561181 in words is "six million, five hundred sixty-one thousand, one hundred eighty-one".