3645317221 has 16 divisors (see below), whose sum is σ = 4578112000. Its totient is φ = 2884203504.

The previous prime is 3645317209. The next prime is 3645317243. The reversal of 3645317221 is 1227135463.

It is not a de Polignac number, because 3645317221 - 2¹¹ = 3645315173 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3645317261) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 404301 + ... + 413218.

It is an arithmetic number, because the mean of its divisors is an integer number (286132000).

Almost surely, 2^3645317221 is an apocalyptic number.

It is an amenable number.

3645317221 is a deficient number, since it is larger than the sum of its proper divisors (932794779).

3645317221 is an equidigital number, since it uses as much as digits as its factorization.

3645317221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 817553 (or 817539 counting only the distinct ones).

The product of its digits is 30240, while the sum is 34.

The square root of 3645317221 is about 60376.4624750407. The cubic root of 3645317221 is about 1539.0229960045.

The spelling of 3645317221 in words is "three billion, six hundred forty-five million, three hundred seventeen thousand, two hundred twenty-one".