1218528400 has 120 divisors (see below), whose sum is σ = 3027634344. Its totient is φ = 470937600.

The previous prime is 1218528391. The next prime is 1218528401. The reversal of 1218528400 is 48258121.

1218528400 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 12 ways, for example, as 4145296 + 1214383104 = 2036^2 + 34848^2 .

It is a super-2 number, since 2×1218528400² = 2969622923213120000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1218528401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4158654 + ... + 4158946.

Almost surely, 2^1218528400 is an apocalyptic number.

1218528400 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 1218528400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1513817172).

1218528400 is an abundant number, since it is smaller than the sum of its proper divisors (1809105944).

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

1218528400 is a wasteful number, since it uses less digits than its factorization.

1218528400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 629 (or 618 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 31.

The square root of 1218528400 is about 34907.4261440170. The cubic root of 1218528400 is about 1068.0999265917.

The spelling of 1218528400 in words is "one billion, two hundred eighteen million, five hundred twenty-eight thousand, four hundred".