1216312200 has 288 divisors, whose sum is σ = 4387219200. Its totient is φ = 312802560.

The previous prime is 1216312159. The next prime is 1216312213. The reversal of 1216312200 is 22136121.

1216312200 is a `hidden beast` number, since 12 + 1 + 631 + 2 + 20 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1408969 + ... + 1409831.

It is an arithmetic number, because the mean of its divisors is an integer number (15233400).

Almost surely, 2^1216312200 is an apocalyptic number.

1216312200 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 1216312200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2193609600).

1216312200 is an abundant number, since it is smaller than the sum of its proper divisors (3170907000).

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

1216312200 is a wasteful number, since it uses less digits than its factorization.

1216312200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 923 (or 902 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 1216312200 is about 34875.6677355431. The cubic root of 1216312200 is about 1067.4519976148.

Adding to 1216312200 its reverse (22136121), we get a palindrome (1238448321).

The spelling of 1216312200 in words is "one billion, two hundred sixteen million, three hundred twelve thousand, two hundred".