5661221 has 12 divisors (see below), whose sum is σ = 6336480. Its totient is φ = 5042880.

The previous prime is 5661217. The next prime is 5661247. The reversal of 5661221 is 1221665.

It is not a de Polignac number, because 5661221 - 2² = 5661217 is a prime.

It is a hoax number, since the sum of its digits (23) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5661281) 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, 4976 + ... + 6006.

It is an arithmetic number, because the mean of its divisors is an integer number (528040).

Almost surely, 2^5661221 is an apocalyptic number.

It is an amenable number.

5661221 is a deficient number, since it is larger than the sum of its proper divisors (675259).

5661221 is a wasteful number, since it uses less digits than its factorization.

5661221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1084 (or 1067 counting only the distinct ones).

The product of its digits is 720, while the sum is 23.

The square root of 5661221 is about 2379.3320491264. The cubic root of 5661221 is about 178.2255798432.

Adding to 5661221 its reverse (1221665), we get a palindrome (6882886).

The spelling of 5661221 in words is "five million, six hundred sixty-one thousand, two hundred twenty-one".