1218391751808 has 288 divisors, whose sum is σ = 4449237221520. Its totient is φ = 316465228800.

The previous prime is 1218391751791. The next prime is 1218391751879. The reversal of 1218391751808 is 8081571938121.

1218391751808 is a `hidden beast` number, since 1 + 2 + 1 + 8 + 391 + 75 + 180 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 360178 + ... + 1602033.

Almost surely, 2^{1218391751808} is an apocalyptic number.

1218391751808 is a gapful number since it is divisible by the number (18) 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 1218391751808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2224618610760).

1218391751808 is an abundant number, since it is smaller than the sum of its proper divisors (3230845469712).

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

1218391751808 is a wasteful number, since it uses less digits than its factorization.

1218391751808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1962256 (or 1962234 counting only the distinct ones).

The product of its (nonzero) digits is 967680, while the sum is 54.

The spelling of 1218391751808 in words is "one trillion, two hundred eighteen billion, three hundred ninety-one million, seven hundred fifty-one thousand, eight hundred eight".