6693021221 has 4 divisors (see below), whose sum is σ = 6697047552. Its totient is φ = 6688994892.

The previous prime is 6693021211. The next prime is 6693021233. The reversal of 6693021221 is 1221203966.

It is a happy number.

6693021221 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1221203966 = 2 ⋅610601983.

It is a cyclic number.

It is not a de Polignac number, because 6693021221 - 2¹⁰ = 6693020197 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 (6693021211) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 2010671 + ... + 2013996.

It is an arithmetic number, because the mean of its divisors is an integer number (1674261888).

Almost surely, 2^6693021221 is an apocalyptic number.

It is an amenable number.

6693021221 is a deficient number, since it is larger than the sum of its proper divisors (4026331).

6693021221 is a wasteful number, since it uses less digits than its factorization.

6693021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4026330.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 6693021221 is about 81810.8869344417. The cubic root of 6693021221 is about 1884.5488553939.

The spelling of 6693021221 in words is "six billion, six hundred ninety-three million, twenty-one thousand, two hundred twenty-one".