21312513144 has 192 divisors, whose sum is σ = 64506624000. Its totient is φ = 6312556800.

The previous prime is 21312513139. The next prime is 21312513151. The reversal of 21312513144 is 44131521312.

21312513144 is a `hidden beast` number, since 2 + 1 + 3 + 1 + 2 + 513 + 144 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5772339 + ... + 5776029.

It is an arithmetic number, because the mean of its divisors is an integer number (335972000).

Almost surely, 2^21312513144 is an apocalyptic number.

21312513144 is a gapful number since it is divisible by the number (24) 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 21312513144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32253312000).

21312513144 is an abundant number, since it is smaller than the sum of its proper divisors (43194110856).

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

21312513144 is a wasteful number, since it uses less digits than its factorization.

21312513144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3946 (or 3939 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The spelling of 21312513144 in words is "twenty-one billion, three hundred twelve million, five hundred thirteen thousand, one hundred forty-four".