21312434412 has 144 divisors (see below), whose sum is σ = 55997192160. Its totient is φ = 6830613504.

The previous prime is 21312434411. The next prime is 21312434419. The reversal of 21312434412 is 21443421312.

21312434412 is a `hidden beast` number, since 2 + 1 + 3 + 1 + 243 + 4 + 412 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (21312434411) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 37455664 + ... + 37456232.

It is an arithmetic number, because the mean of its divisors is an integer number (388869390).

Almost surely, 2^21312434412 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 21312434412, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27998596080).

21312434412 is an abundant number, since it is smaller than the sum of its proper divisors (34684757748).

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

21312434412 is a wasteful number, since it uses less digits than its factorization.

21312434412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 992 (or 987 counting only the distinct ones).

The product of its digits is 4608, while the sum is 27.

Adding to 21312434412 its reverse (21443421312), we get a palindrome (42755855724).

The spelling of 21312434412 in words is "twenty-one billion, three hundred twelve million, four hundred thirty-four thousand, four hundred twelve".