3021661 has 4 divisors (see below), whose sum is σ = 3041824. Its totient is φ = 3001500.

The previous prime is 3021649. The next prime is 3021691. The reversal of 3021661 is 1661203.

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: 1661203 = 211 ⋅7873.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3021661 is a prime.

It is a Duffinian number.

3021661 is a modest number, since divided by 1661 gives 302 as remainder.

3021661 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3021611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9855 + ... + 10156.

It is an arithmetic number, because the mean of its divisors is an integer number (760456).

Almost surely, 2^3021661 is an apocalyptic number.

It is an amenable number.

3021661 is a deficient number, since it is larger than the sum of its proper divisors (20163).

3021661 is a wasteful number, since it uses less digits than its factorization.

3021661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20162.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 3021661 is about 1738.2925530531. The cubic root of 3021661 is about 144.5712423530.

Adding to 3021661 its reverse (1661203), we get a palindrome (4682864).

The spelling of 3021661 in words is "three million, twenty-one thousand, six hundred sixty-one".