1216911600 has 450 divisors, whose sum is σ = 4629844296. Its totient is φ = 306028800.

The previous prime is 1216911599. The next prime is 1216911607. The reversal of 1216911600 is 61196121.

It is a tau number, because it is divible by the number of its divisors (450).

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 (1216911607) by changing a digit.

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 89 ways as a sum of consecutive naturals, for example, 17139565 + ... + 17139635.

Almost surely, 2^1216911600 is an apocalyptic number.

1216911600 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 1216911600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2314922148).

1216911600 is an abundant number, since it is smaller than the sum of its proper divisors (3412932696).

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

1216911600 is a wasteful number, since it uses less digits than its factorization.

1216911600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147 (or 104 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 1216911600 is about 34884.2600609501. The cubic root of 1216911600 is about 1067.6273159947.

The spelling of 1216911600 in words is "one billion, two hundred sixteen million, nine hundred eleven thousand, six hundred".