21311431434 has 96 divisors (see below), whose sum is σ = 50350248000. Its totient is φ = 6488923392.

The previous prime is 21311431381. The next prime is 21311431439. The reversal of 21311431434 is 43413411312.

21311431434 is a `hidden beast` number, since 2 + 1 + 311 + 4 + 314 + 34 = 666.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21311431398 and 21311431407.

It is not an unprimeable number, because it can be changed into a prime (21311431439) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 12783469 + ... + 12785135.

It is an arithmetic number, because the mean of its divisors is an integer number (524481750).

Almost surely, 2^21311431434 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21311431434, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25175124000).

21311431434 is an abundant number, since it is smaller than the sum of its proper divisors (29038816566).

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

21311431434 is a wasteful number, since it uses less digits than its factorization.

21311431434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3012 (or 3009 counting only the distinct ones).

The product of its digits is 3456, while the sum is 27.

Adding to 21311431434 its reverse (43413411312), we get a palindrome (64724842746).

The spelling of 21311431434 in words is "twenty-one billion, three hundred eleven million, four hundred thirty-one thousand, four hundred thirty-four".