1218203280 has 640 divisors, whose sum is σ = 5211095040. Its totient is φ = 255467520.

The previous prime is 1218203279. The next prime is 1218203317. The reversal of 1218203280 is 823028121.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 10780504 + ... + 10780616.

It is an arithmetic number, because the mean of its divisors is an integer number (8142336).

Almost surely, 2^1218203280 is an apocalyptic number.

1218203280 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 1218203280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2605547520).

1218203280 is an abundant number, since it is smaller than the sum of its proper divisors (3992891760).

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

1218203280 is a wasteful number, since it uses less digits than its factorization.

1218203280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196 (or 184 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 1218203280 is about 34902.7689445981. The cubic root of 1218203280 is about 1068.0049235981.

The spelling of 1218203280 in words is "one billion, two hundred eighteen million, two hundred three thousand, two hundred eighty".