4091661 has 16 divisors (see below), whose sum is σ = 6928000. Its totient is φ = 2337984.

The previous prime is 4091657. The next prime is 4091663. The reversal of 4091661 is 1661904.

It is not a de Polignac number, because 4091661 - 2² = 4091657 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4091663) 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, 10636 + ... + 11013.

It is an arithmetic number, because the mean of its divisors is an integer number (433000).

Almost surely, 2^4091661 is an apocalyptic number.

It is an amenable number.

4091661 is a deficient number, since it is larger than the sum of its proper divisors (2836339).

4091661 is a wasteful number, since it uses less digits than its factorization.

4091661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21665 (or 21659 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 4091661 is about 2022.7854557515. The cubic root of 4091661 is about 159.9434826427.

The spelling of 4091661 in words is "four million, ninety-one thousand, six hundred sixty-one".