3660221 has 2 divisors, whose sum is σ = 3660222. Its totient is φ = 3660220.

The previous prime is 3660211. The next prime is 3660259. The reversal of 3660221 is 1220663.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2208196 + 1452025 = 1486^2 + 1205^2 .

It is an emirp because it is prime and its reverse (1220663) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3660221 is a prime.

It is a super-3 number, since 3×3660221³ (a number of 21 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 3660193 and 3660202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3660211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1830110 + 1830111.

It is an arithmetic number, because the mean of its divisors is an integer number (1830111).

Almost surely, 2^3660221 is an apocalyptic number.

It is an amenable number.

3660221 is a deficient number, since it is larger than the sum of its proper divisors (1).

3660221 is an equidigital number, since it uses as much as digits as its factorization.

3660221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 3660221 is about 1913.1704053743. The cubic root of 3660221 is about 154.1117561770. Note that the first 3 decimals are identical.

Adding to 3660221 its reverse (1220663), we get a palindrome (4880884).

The spelling of 3660221 in words is "three million, six hundred sixty thousand, two hundred twenty-one".