6643021522 has 4 divisors (see below), whose sum is σ = 9964532286. Its totient is φ = 3321510760.

The previous prime is 6643021519. The next prime is 6643021571. The reversal of 6643021522 is 2251203466.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 2251203466 = 2 ⋅1125601733.

It can be written as a sum of positive squares in only one way, i.e., 5814215001 + 828806521 = 76251^2 + 28789^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1660755379 + ... + 1660755382.

Almost surely, 2^6643021522 is an apocalyptic number.

6643021522 is a deficient number, since it is larger than the sum of its proper divisors (3321510764).

6643021522 is a wasteful number, since it uses less digits than its factorization.

6643021522 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3321510763.

The product of its (nonzero) digits is 17280, while the sum is 31.

The square root of 6643021522 is about 81504.7331263651. The cubic root of 6643021522 is about 1879.8443286297.

Adding to 6643021522 its reverse (2251203466), we get a palindrome (8894224988).

The spelling of 6643021522 in words is "six billion, six hundred forty-three million, twenty-one thousand, five hundred twenty-two".