3639221 has 4 divisors (see below), whose sum is σ = 3797472. Its totient is φ = 3480972.

The previous prime is 3639217. The next prime is 3639277. The reversal of 3639221 is 1229363.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1229363 = 571 ⋅2153.

It is a cyclic number.

It is not a de Polignac number, because 3639221 - 2² = 3639217 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3639211) 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, 79091 + ... + 79136.

It is an arithmetic number, because the mean of its divisors is an integer number (949368).

Almost surely, 2^3639221 is an apocalyptic number.

It is an amenable number.

3639221 is a deficient number, since it is larger than the sum of its proper divisors (158251).

3639221 is a wasteful number, since it uses less digits than its factorization.

3639221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158250.

The product of its digits is 1944, while the sum is 26.

The square root of 3639221 is about 1907.6742384380. The cubic root of 3639221 is about 153.8164592496.

The spelling of 3639221 in words is "three million, six hundred thirty-nine thousand, two hundred twenty-one".