1216814400 has 420 divisors, whose sum is σ = 4601801820. Its totient is φ = 315187200.

The previous prime is 1216814383. The next prime is 1216814411. The reversal of 1216814400 is 44186121.

It is a happy number.

1216814400 is a `hidden beast` number, since 1 + 216 + 8 + 1 + 440 + 0 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 32353344 + 1184461056 = 5688^2 + 34416^2 .

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 59 ways as a sum of consecutive naturals, for example, 5313486 + ... + 5313714.

It is an arithmetic number, because the mean of its divisors is an integer number (10956671).

Almost surely, 2^1216814400 is an apocalyptic number.

1216814400 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 1216814400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2300900910).

1216814400 is an abundant number, since it is smaller than the sum of its proper divisors (3384987420).

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

1216814400 is a wasteful number, since it uses less digits than its factorization.

1216814400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 304 (or 280 counting only the distinct ones).

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

The square root of 1216814400 is about 34882.8668546609. The cubic root of 1216814400 is about 1067.5988898986.

The spelling of 1216814400 in words is "one billion, two hundred sixteen million, eight hundred fourteen thousand, four hundred".