6721615020 has 24 divisors (see below), whose sum is σ = 18820522224. Its totient is φ = 1792430656.

The previous prime is 6721615003. The next prime is 6721615031. The reversal of 6721615020 is 205161276.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56013399 + ... + 56013518.

It is an arithmetic number, because the mean of its divisors is an integer number (784188426).

Almost surely, 2^6721615020 is an apocalyptic number.

6721615020 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6721615020 is an abundant number, since it is smaller than the sum of its proper divisors (12098907204).

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

6721615020 is a wasteful number, since it uses less digits than its factorization.

6721615020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112026929 (or 112026927 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 30.

The square root of 6721615020 is about 81985.4561492464. The cubic root of 6721615020 is about 1887.2287540282.

Adding to 6721615020 its reverse (205161276), we get a palindrome (6926776296).

The spelling of 6721615020 in words is "six billion, seven hundred twenty-one million, six hundred fifteen thousand, twenty".