3643155221 has 2 divisors, whose sum is σ = 3643155222. Its totient is φ = 3643155220.

The previous prime is 3643155211. The next prime is 3643155223. The reversal of 3643155221 is 1225513463.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2121063025 + 1522092196 = 46055^2 + 39014^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3643155221 is a prime.

Together with 3643155223, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3643155223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1821577610 + 1821577611.

It is an arithmetic number, because the mean of its divisors is an integer number (1821577611).

Almost surely, 2^3643155221 is an apocalyptic number.

It is an amenable number.

3643155221 is a deficient number, since it is larger than the sum of its proper divisors (1).

3643155221 is an equidigital number, since it uses as much as digits as its factorization.

3643155221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21600, while the sum is 32.

The square root of 3643155221 is about 60358.5554913303. Note that the first 3 decimals coincide. The cubic root of 3643155221 is about 1538.7186762849.

Adding to 3643155221 its reverse (1225513463), we get a palindrome (4868668684).

The spelling of 3643155221 in words is "three billion, six hundred forty-three million, one hundred fifty-five thousand, two hundred twenty-one".