218915648640 has 768 divisors, whose sum is σ = 860775552000. Its totient is φ = 50859933696.

The previous prime is 218915648603. The next prime is 218915648669. The reversal of 218915648640 is 46846519812.

218915648640 is a `hidden beast` number, since 2 + 1 + 8 + 9 + 156 + 486 + 4 + 0 = 666.

It is a super-2 number, since 2×218915648640² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

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 95 ways as a sum of consecutive naturals, for example, 136056156 + ... + 136057764.

It is an arithmetic number, because the mean of its divisors is an integer number (1120801500).

Almost surely, 2^218915648640 is an apocalyptic number.

218915648640 is a gapful number since it is divisible by the number (20) 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 218915648640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (430387776000).

218915648640 is an abundant number, since it is smaller than the sum of its proper divisors (641859903360).

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

218915648640 is a wasteful number, since it uses less digits than its factorization.

218915648640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1749 (or 1734 counting only the distinct ones).

The product of its (nonzero) digits is 3317760, while the sum is 54.

The spelling of 218915648640 in words is "two hundred eighteen billion, nine hundred fifteen million, six hundred forty-eight thousand, six hundred forty".