3221636821 has 8 divisors (see below), whose sum is σ = 3473487360. Its totient is φ = 2970362352.

The previous prime is 3221636801. The next prime is 3221636851. The reversal of 3221636821 is 1286361223.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 3221636821 - 2⁹ = 3221636309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3221636801) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 132361 + ... + 154798.

It is an arithmetic number, because the mean of its divisors is an integer number (434185920).

Almost surely, 2^3221636821 is an apocalyptic number.

It is an amenable number.

3221636821 is a deficient number, since it is larger than the sum of its proper divisors (251850539).

3221636821 is a wasteful number, since it uses less digits than its factorization.

3221636821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288035.

The product of its digits is 20736, while the sum is 34.

The square root of 3221636821 is about 56759.4645940217. The cubic root of 3221636821 is about 1476.9264222498.

The spelling of 3221636821 in words is "three billion, two hundred twenty-one million, six hundred thirty-six thousand, eight hundred twenty-one".