1216610208 has 288 divisors, whose sum is σ = 4019258880. Its totient is φ = 345438720.

The previous prime is 1216610203. The next prime is 1216610243. The reversal of 1216610208 is 8020166121.

1216610208 is a `hidden beast` number, since 1 + 21 + 6 + 610 + 20 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216610201) 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, 4298835 + ... + 4299117.

It is an arithmetic number, because the mean of its divisors is an integer number (13955760).

Almost surely, 2^1216610208 is an apocalyptic number.

1216610208 is a gapful number since it is divisible by the number (18) 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 1216610208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2009629440).

1216610208 is an abundant number, since it is smaller than the sum of its proper divisors (2802648672).

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

1216610208 is a wasteful number, since it uses less digits than its factorization.

1216610208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 392 (or 381 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 1216610208 is about 34879.9399082051. The cubic root of 1216610208 is about 1067.5391691098.

Adding to 1216610208 its reverse (8020166121), we get a palindrome (9236776329).

The spelling of 1216610208 in words is "one billion, two hundred sixteen million, six hundred ten thousand, two hundred eight".