4181661 has 12 divisors (see below), whose sum is σ = 6589440. Its totient is φ = 2534280.

The previous prime is 4181657. The next prime is 4181669. The reversal of 4181661 is 1661814.

4181661 = T₅₄₃ + T₅₄₄ + ... + T₅₆₉.

It is not a de Polignac number, because 4181661 - 2² = 4181657 is a prime.

It is an Ulam number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4181669) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21021 + ... + 21218.

It is an arithmetic number, because the mean of its divisors is an integer number (549120).

Almost surely, 2^4181661 is an apocalyptic number.

It is an amenable number.

4181661 is a deficient number, since it is larger than the sum of its proper divisors (2407779).

4181661 is a wasteful number, since it uses less digits than its factorization.

4181661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42256 (or 42253 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 4181661 is about 2044.9110005083. The cubic root of 4181661 is about 161.1076912825.

The spelling of 4181661 in words is "four million, one hundred eighty-one thousand, six hundred sixty-one".