1218392017920 has 3168 divisors, whose sum is σ = 5871212605440. Its totient is φ = 227731046400.

The previous prime is 1218392017907. The next prime is 1218392017981. The reversal of 1218392017920 is 297102938121.

It is a tau number, because it is divible by the number of its divisors (3168).

It is a super-2 number, since 2×1218392017920² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 22988528614 + ... + 22988528666.

Almost surely, 2^{1218392017920} is an apocalyptic number.

1218392017920 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 1218392017920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2935606302720).

1218392017920 is an abundant number, since it is smaller than the sum of its proper divisors (4652820587520).

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

1218392017920 is a wasteful number, since it uses less digits than its factorization.

1218392017920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163 (or 131 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 45.

The spelling of 1218392017920 in words is "one trillion, two hundred eighteen billion, three hundred ninety-two million, seventeen thousand, nine hundred twenty".