1216828400 has 120 divisors (see below), whose sum is σ = 3183985200. Its totient is φ = 445132800.

The previous prime is 1216828373. The next prime is 1216828411. The reversal of 1216828400 is 48286121.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 217640 + ... + 223160.

It is an arithmetic number, because the mean of its divisors is an integer number (26533210).

Almost surely, 2^1216828400 is an apocalyptic number.

1216828400 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 1216828400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1591992600).

1216828400 is an abundant number, since it is smaller than the sum of its proper divisors (1967156800).

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

1216828400 is a wasteful number, since it uses less digits than its factorization.

1216828400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5587 (or 5576 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 32.

The square root of 1216828400 is about 34883.0675256635. The cubic root of 1216828400 is about 1067.6029842856.

The spelling of 1216828400 in words is "one billion, two hundred sixteen million, eight hundred twenty-eight thousand, four hundred".