5665221 has 10 divisors (see below), whose sum is σ = 8462982. Its totient is φ = 3776760.

The previous prime is 5665217. The next prime is 5665243. The reversal of 5665221 is 1225665.

5665221 is a `hidden beast` number, since 5 + 6 + 652 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 3744225 + 1920996 = 1935^2 + 1386^2 .

It is not a de Polignac number, because 5665221 - 2² = 5665217 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5669221) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 34890 + ... + 35051.

Almost surely, 2^5665221 is an apocalyptic number.

It is an amenable number.

5665221 is a deficient number, since it is larger than the sum of its proper divisors (2797761).

5665221 is an equidigital number, since it uses as much as digits as its factorization.

5665221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69953 (or 69944 counting only the distinct ones).

The product of its digits is 3600, while the sum is 27.

The square root of 5665221 is about 2380.1724727423. The cubic root of 5665221 is about 178.2675457302.

It can be divided in two parts, 5665 and 221, that added together give a triangular number (5886 = T₁₀₈).

The spelling of 5665221 in words is "five million, six hundred sixty-five thousand, two hundred twenty-one".