21235012344 has 192 divisors, whose sum is σ = 70981310400. Its totient is φ = 5584785408.

The previous prime is 21235012339. The next prime is 21235012363. The reversal of 21235012344 is 44321053212.

21235012344 is a `hidden beast` number, since 2 + 123 + 501 + 2 + 34 + 4 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2439552 + ... + 2448240.

It is an arithmetic number, because the mean of its divisors is an integer number (369694325).

Almost surely, 2^21235012344 is an apocalyptic number.

21235012344 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 21235012344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35490655200).

21235012344 is an abundant number, since it is smaller than the sum of its proper divisors (49746298056).

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

21235012344 is a wasteful number, since it uses less digits than its factorization.

21235012344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9094 (or 9087 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

Adding to 21235012344 its reverse (44321053212), we get a palindrome (65556065556).

The spelling of 21235012344 in words is "twenty-one billion, two hundred thirty-five million, twelve thousand, three hundred forty-four".