7217478918 has 80 divisors (see below), whose sum is σ = 17579857680. Its totient is φ = 2199939264.

The previous prime is 7217478901. The next prime is 7217478923. The reversal of 7217478918 is 8198747127.

7217478918 is a `hidden beast` number, since 72 + 17 + 478 + 91 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 209328 + ... + 241356.

It is an arithmetic number, because the mean of its divisors is an integer number (219748221).

Almost surely, 2^7217478918 is an apocalyptic number.

7217478918 is a gapful number since it is divisible by the number (78) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 7217478918, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8789928840).

7217478918 is an abundant number, since it is smaller than the sum of its proper divisors (10362378762).

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

7217478918 is a wasteful number, since it uses less digits than its factorization.

7217478918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32163 (or 32154 counting only the distinct ones).

The product of its digits is 1580544, while the sum is 54.

The square root of 7217478918 is about 84955.7468215070. The cubic root of 7217478918 is about 1932.5400721920.

The spelling of 7217478918 in words is "seven billion, two hundred seventeen million, four hundred seventy-eight thousand, nine hundred eighteen".