6620221644 has 24 divisors (see below), whose sum is σ = 15515239488. Its totient is φ = 2197018320.

The previous prime is 6620221639. The next prime is 6620221667. The reversal of 6620221644 is 4461220266.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1212442 + ... + 1217889.

It is an arithmetic number, because the mean of its divisors is an integer number (646468312).

Almost surely, 2^6620221644 is an apocalyptic number.

It is an amenable number.

6620221644 is an abundant number, since it is smaller than the sum of its proper divisors (8895017844).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6620221644 is a wasteful number, since it uses less digits than its factorization.

6620221644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2430565 (or 2430563 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 33.

The square root of 6620221644 is about 81364.7444781829. The cubic root of 6620221644 is about 1877.6912245929.

The spelling of 6620221644 in words is "six billion, six hundred twenty million, two hundred twenty-one thousand, six hundred forty-four".