218681779379448 has 768 divisors, whose sum is σ = 743799084134400. Its totient is φ = 52240107110400.

The previous prime is 218681779379447. The next prime is 218681779379471. The reversal of 218681779379448 is 844973977186812.

It is a Cunningham number, because it is equal to 14787893²-1.

It is a Harshad number since it is a multiple of its sum of digits (84).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218681779379447) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 10735999408 + ... + 10736019776.

It is an arithmetic number, because the mean of its divisors is an integer number (968488390800).

Almost surely, 2^{218681779379448} is an apocalyptic number.

218681779379448 is a gapful number since it is divisible by the number (28) 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 218681779379448, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (371899542067200).

218681779379448 is an abundant number, since it is smaller than the sum of its proper divisors (525117304754952).

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

218681779379448 is a wasteful number, since it uses less digits than its factorization.

218681779379448 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21132 (or 21117 counting only the distinct ones).

The product of its digits is 8193540096, while the sum is 84.

The spelling of 218681779379448 in words is "two hundred eighteen trillion, six hundred eighty-one billion, seven hundred seventy-nine million, three hundred seventy-nine thousand, four hundred forty-eight".