6645632201 has 4 divisors (see below), whose sum is σ = 7156834692. Its totient is φ = 6134429712.

The previous prime is 6645632183. The next prime is 6645632269. The reversal of 6645632201 is 1022365466.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1003368976 + 5642263225 = 31676^2 + 75115^2 .

It is a cyclic number.

It is not a de Polignac number, because 6645632201 - 2¹⁴ = 6645615817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6645632101) 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, 255601226 + ... + 255601251.

It is an arithmetic number, because the mean of its divisors is an integer number (1789208673).

Almost surely, 2^6645632201 is an apocalyptic number.

It is an amenable number.

6645632201 is a deficient number, since it is larger than the sum of its proper divisors (511202491).

6645632201 is a wasteful number, since it uses less digits than its factorization.

6645632201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 511202490.

The product of its (nonzero) digits is 51840, while the sum is 35.

The square root of 6645632201 is about 81520.7470586476. The cubic root of 6645632201 is about 1880.0905533001.

Adding to 6645632201 its reverse (1022365466), we get a palindrome (7667997667).

The spelling of 6645632201 in words is "six billion, six hundred forty-five million, six hundred thirty-two thousand, two hundred one".