6421720600 has 24 divisors (see below), whose sum is σ = 14930500860. Its totient is φ = 2568688160.

The previous prime is 6421720549. The next prime is 6421720609. The reversal of 6421720600 is 60271246.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6421720609) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 16054102 + ... + 16054501.

Almost surely, 2^6421720600 is an apocalyptic number.

It is an amenable number.

6421720600 is an abundant number, since it is smaller than the sum of its proper divisors (8508780260).

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

6421720600 is a wasteful number, since it uses less digits than its factorization.

6421720600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32108619 (or 32108610 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 6421720600 is about 80135.6387632868. The cubic root of 6421720600 is about 1858.7335387651.

Adding to 6421720600 its reverse (60271246), we get a palindrome (6481991846).

The spelling of 6421720600 in words is "six billion, four hundred twenty-one million, seven hundred twenty thousand, six hundred".