6623721000 has 512 divisors, whose sum is σ = 25096780800. Its totient is φ = 1606348800.

The previous prime is 6623720933. The next prime is 6623721001. The reversal of 6623721000 is 1273266.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (6623721001) 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 127 ways as a sum of consecutive naturals, for example, 39662917 + ... + 39663083.

It is an arithmetic number, because the mean of its divisors is an integer number (49017150).

Almost surely, 2^6623721000 is an apocalyptic number.

6623721000 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6623721000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12548390400).

6623721000 is an abundant number, since it is smaller than the sum of its proper divisors (18473059800).

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

6623721000 is a wasteful number, since it uses less digits than its factorization.

6623721000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 323 (or 303 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 27.

The square root of 6623721000 is about 81386.2457667142. The cubic root of 6623721000 is about 1878.0220067035.

Adding to 6623721000 its reverse (1273266), we get a palindrome (6624994266).

The spelling of 6623721000 in words is "six billion, six hundred twenty-three million, seven hundred twenty-one thousand".