1216604178 has 64 divisors (see below), whose sum is σ = 2789808000. Its totient is φ = 392703552.

The previous prime is 1216604177. The next prime is 1216604183. The reversal of 1216604178 is 8714066121.

It is a happy number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1216604171) 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 31 ways as a sum of consecutive naturals, for example, 456213 + ... + 458871.

It is an arithmetic number, because the mean of its divisors is an integer number (43590750).

Almost surely, 2^1216604178 is an apocalyptic number.

1216604178 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1216604178, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1394904000).

1216604178 is an abundant number, since it is smaller than the sum of its proper divisors (1573203822).

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

1216604178 is a wasteful number, since it uses less digits than its factorization.

1216604178 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2936 (or 2930 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 1216604178 is about 34879.8534687289. The cubic root of 1216604178 is about 1067.5374053918.

The spelling of 1216604178 in words is "one billion, two hundred sixteen million, six hundred four thousand, one hundred seventy-eight".