1216382400 has 336 divisors, whose sum is σ = 4559990880. Its totient is φ = 315187200.

The previous prime is 1216382399. The next prime is 1216382407. The reversal of 1216382400 is 42836121.

1216382400 is a `hidden beast` number, since 1 + 2 + 1 + 638 + 24 + 0 + 0 = 666.

It is a super-2 number, since 2×1216382400² = 2959172286059520000, which contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216382407) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1598020 + ... + 1598780.

Almost surely, 2^1216382400 is an apocalyptic number.

1216382400 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 1216382400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2279995440).

1216382400 is an abundant number, since it is smaller than the sum of its proper divisors (3343608480).

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

1216382400 is a wasteful number, since it uses less digits than its factorization.

1216382400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 829 (or 808 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 1216382400 is about 34876.6741533650. The cubic root of 1216382400 is about 1067.4725333755.

The spelling of 1216382400 in words is "one billion, two hundred sixteen million, three hundred eighty-two thousand, four hundred".