3661661 has 8 divisors (see below), whose sum is σ = 3878400. Its totient is φ = 3447360.

The previous prime is 3661649. The next prime is 3661673. The reversal of 3661661 is 1661663.

It is an interprime number because it is at equal distance from previous prime (3661649) and next prime (3661673).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 3661661 - 2⁶ = 3661597 is a prime.

It is a super-2 number, since 2×3661661² = 26815522557842, 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 (3661601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3125 + ... + 4133.

It is an arithmetic number, because the mean of its divisors is an integer number (484800).

Almost surely, 2^3661661 is an apocalyptic number.

It is an amenable number.

3661661 is a deficient number, since it is larger than the sum of its proper divisors (216739).

3661661 is a wasteful number, since it uses less digits than its factorization.

3661661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1219.

The product of its digits is 3888, while the sum is 29.

The square root of 3661661 is about 1913.5467070338. The cubic root of 3661661 is about 154.1319636848.

The spelling of 3661661 in words is "three million, six hundred sixty-one thousand, six hundred sixty-one".