3668821 has 12 divisors (see below), whose sum is σ = 4209732. Its totient is φ = 3184896.

The previous prime is 3668807. The next prime is 3668837. The reversal of 3668821 is 1288663.

It can be written as a sum of positive squares in 6 ways, for example, as 96721 + 3572100 = 311^2 + 1890^2 .

It is not a de Polignac number, because 3668821 - 2¹⁵ = 3636053 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3668801) 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, 2235 + ... + 3511.

It is an arithmetic number, because the mean of its divisors is an integer number (350811).

Almost surely, 2^3668821 is an apocalyptic number.

It is an amenable number.

3668821 is a deficient number, since it is larger than the sum of its proper divisors (540911).

3668821 is a wasteful number, since it uses less digits than its factorization.

3668821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1320 (or 1307 counting only the distinct ones).

The product of its digits is 13824, while the sum is 34.

The square root of 3668821 is about 1915.4166648539. The cubic root of 3668821 is about 154.2323613208.

It can be divided in two parts, 3668 and 821, that added together give a square (4489 = 67²).

The spelling of 3668821 in words is "three million, six hundred sixty-eight thousand, eight hundred twenty-one".