1218611599920 has 1280 divisors, whose sum is σ = 5171069030400. Its totient is φ = 259555000320.

The previous prime is 1218611599871. The next prime is 1218611599957. The reversal of 1218611599920 is 299951168121.

1218611599920 is a `hidden beast` number, since 1 + 2 + 18 + 6 + 11 + 599 + 9 + 20 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 2394128626 + ... + 2394129134.

It is an arithmetic number, because the mean of its divisors is an integer number (4039897680).

Almost surely, 2^{1218611599920} is an apocalyptic number.

1218611599920 is a gapful number since it is divisible by the number (10) 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 1218611599920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2585534515200).

1218611599920 is an abundant number, since it is smaller than the sum of its proper divisors (3952457430480).

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

1218611599920 is a wasteful number, since it uses less digits than its factorization.

1218611599920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 915 (or 903 counting only the distinct ones).

The product of its (nonzero) digits is 699840, while the sum is 54.

The spelling of 1218611599920 in words is "one trillion, two hundred eighteen billion, six hundred eleven million, five hundred ninety-nine thousand, nine hundred twenty".