6621436221 has 24 divisors (see below), whose sum is σ = 8959097664. Its totient is φ = 4349779200.

The previous prime is 6621436219. The next prime is 6621436291. The reversal of 6621436221 is 1226341266.

6621436221 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 6621436221 - 2¹ = 6621436219 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6621436201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11165701 + ... + 11166293.

It is an arithmetic number, because the mean of its divisors is an integer number (373295736).

Almost surely, 2^6621436221 is an apocalyptic number.

It is an amenable number.

6621436221 is a deficient number, since it is larger than the sum of its proper divisors (2337661443).

6621436221 is a wasteful number, since it uses less digits than its factorization.

6621436221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1061 (or 904 counting only the distinct ones).

The product of its digits is 20736, while the sum is 33.

The square root of 6621436221 is about 81372.2079152336. The cubic root of 6621436221 is about 1877.8060475924.

Adding to 6621436221 its reverse (1226341266), we get a palindrome (7847777487).

The spelling of 6621436221 in words is "six billion, six hundred twenty-one million, four hundred thirty-six thousand, two hundred twenty-one".