1218218400 has 432 divisors, whose sum is σ = 5129671680. Its totient is φ = 278208000.

The previous prime is 1218218381. The next prime is 1218218461. The reversal of 1218218400 is 48128121.

It is a tau number, because it is divible by the number of its divisors (432).

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1057825 + ... + 1058975.

It is an arithmetic number, because the mean of its divisors is an integer number (11874240).

Almost surely, 2^1218218400 is an apocalyptic number.

1218218400 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 1218218400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2564835840).

1218218400 is an abundant number, since it is smaller than the sum of its proper divisors (3911453280).

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

1218218400 is a wasteful number, since it uses less digits than its factorization.

1218218400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1194 (or 1168 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 27.

The square root of 1218218400 is about 34902.9855456521. The cubic root of 1218218400 is about 1068.0093421730.

The spelling of 1218218400 in words is "one billion, two hundred eighteen million, two hundred eighteen thousand, four hundred".