21243113424 has 180 divisors, whose sum is σ = 64774041696. Its totient is φ = 6495959808.

The previous prime is 21243113417. The next prime is 21243113431. The reversal of 21243113424 is 42431134212.

21243113424 is a `hidden beast` number, since 2 + 1 + 2 + 4 + 311 + 342 + 4 = 666.

It is an interprime number because it is at equal distance from previous prime (21243113417) and next prime (21243113431).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 4061499 + ... + 4066725.

Almost surely, 2^21243113424 is an apocalyptic number.

21243113424 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 21243113424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32387020848).

21243113424 is an abundant number, since it is smaller than the sum of its proper divisors (43530928272).

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

21243113424 is a wasteful number, since it uses less digits than its factorization.

21243113424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5434 (or 5412 counting only the distinct ones).

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

Adding to 21243113424 its reverse (42431134212), we get a palindrome (63674247636).

The spelling of 21243113424 in words is "twenty-one billion, two hundred forty-three million, one hundred thirteen thousand, four hundred twenty-four".