7218686720 has 144 divisors (see below), whose sum is σ = 20801706240. Its totient is φ = 2344660992.

The previous prime is 7218686719. The next prime is 7218686743. The reversal of 7218686720 is 276868127.

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 15 ways as a sum of consecutive naturals, for example, 149039 + ... + 191441.

Almost surely, 2^7218686720 is an apocalyptic number.

7218686720 is a gapful number since it is divisible by the number (70) 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 7218686720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10400853120).

7218686720 is an abundant number, since it is smaller than the sum of its proper divisors (13583019520).

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

7218686720 is a wasteful number, since it uses less digits than its factorization.

7218686720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42450 (or 42436 counting only the distinct ones).

The product of its (nonzero) digits is 451584, while the sum is 47.

The square root of 7218686720 is about 84962.8549426160. The cubic root of 7218686720 is about 1932.6478658599.

The spelling of 7218686720 in words is "seven billion, two hundred eighteen million, six hundred eighty-six thousand, seven hundred twenty".