6661181 has 4 divisors (see below), whose sum is σ = 6676032. Its totient is φ = 6646332.

The previous prime is 6661157. The next prime is 6661189. The reversal of 6661181 is 1811666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1811666 = 2 ⋅905833.

It is a cyclic number.

It is not a de Polignac number, because 6661181 - 2⁶ = 6661117 is a prime.

It is a super-2 number, since 2×6661181² = 88742664629522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6661189) 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, 6731 + ... + 7656.

It is an arithmetic number, because the mean of its divisors is an integer number (1669008).

Almost surely, 2^6661181 is an apocalyptic number.

It is an amenable number.

6661181 is a deficient number, since it is larger than the sum of its proper divisors (14851).

6661181 is a wasteful number, since it uses less digits than its factorization.

6661181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14850.

The product of its digits is 1728, while the sum is 29.

The square root of 6661181 is about 2580.9263840722. The cubic root of 6661181 is about 188.1555695109.

The spelling of 6661181 in words is "six million, six hundred sixty-one thousand, one hundred eighty-one".