3657221 has 4 divisors (see below), whose sum is σ = 3692832. Its totient is φ = 3621612.

The previous prime is 3657217. The next prime is 3657223. The reversal of 3657221 is 1227563.

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.

It is a cyclic number.

It is not a de Polignac number, because 3657221 - 2² = 3657217 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3657223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17651 + ... + 17856.

It is an arithmetic number, because the mean of its divisors is an integer number (923208).

Almost surely, 2^3657221 is an apocalyptic number.

It is an amenable number.

3657221 is a deficient number, since it is larger than the sum of its proper divisors (35611).

3657221 is a wasteful number, since it uses less digits than its factorization.

3657221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35610.

The product of its digits is 2520, while the sum is 26.

The square root of 3657221 is about 1912.3862057649. The cubic root of 3657221 is about 154.0696401737.

The spelling of 3657221 in words is "three million, six hundred fifty-seven thousand, two hundred twenty-one".