1216231212636 has 240 divisors, whose sum is σ = 3685662443232. Its totient is φ = 345635942400.

The previous prime is 1216231212611. The next prime is 1216231212641. The reversal of 1216231212636 is 6362121326121.

1216231212636 is a `hidden beast` number, since 1 + 2 + 1 + 6 + 2 + 3 + 1 + 2 + 12 + 636 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 1216231212636.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 16989510 + ... + 17060946.

Almost surely, 2^{1216231212636} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1216231212636, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1842831221616).

1216231212636 is an abundant number, since it is smaller than the sum of its proper divisors (2469431230596).

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

1216231212636 is a wasteful number, since it uses less digits than its factorization.

1216231212636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71762 (or 71751 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

Adding to 1216231212636 its reverse (6362121326121), we get a palindrome (7578352538757).

The spelling of 1216231212636 in words is "one trillion, two hundred sixteen billion, two hundred thirty-one million, two hundred twelve thousand, six hundred thirty-six".