21132431424 has 168 divisors, whose sum is σ = 65319701720. Its totient is φ = 6493519872.

The previous prime is 21132431407. The next prime is 21132431443. The reversal of 21132431424 is 42413423112.

21132431424 is a `hidden beast` number, since 2 + 1 + 1 + 324 + 314 + 24 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1034265600 + 20098165824 = 32160^2 + 141768^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7553994 + ... + 7556790.

Almost surely, 2^21132431424 is an apocalyptic number.

21132431424 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 21132431424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32659850860).

21132431424 is an abundant number, since it is smaller than the sum of its proper divisors (44187270296).

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

21132431424 is a wasteful number, since it uses less digits than its factorization.

21132431424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3837 (or 3824 counting only the distinct ones).

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

Adding to 21132431424 its reverse (42413423112), we get a palindrome (63545854536).

The spelling of 21132431424 in words is "twenty-one billion, one hundred thirty-two million, four hundred thirty-one thousand, four hundred twenty-four".