21403234424 has 32 divisors (see below), whose sum is σ = 47146987440. Its totient is φ = 8980377600.

The previous prime is 21403234423. The next prime is 21403234451. The reversal of 21403234424 is 42443230412.

It is a super-2 number, since 2×21403234424² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21403234423) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9353417 + ... + 9355704.

Almost surely, 2^21403234424 is an apocalyptic number.

It is an amenable number.

21403234424 is an abundant number, since it is smaller than the sum of its proper divisors (25743753016).

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

21403234424 is a wasteful number, since it uses less digits than its factorization.

21403234424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18709151 (or 18709147 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 29.

Adding to 21403234424 its reverse (42443230412), we get a palindrome (63846464836).

The spelling of 21403234424 in words is "twenty-one billion, four hundred three million, two hundred thirty-four thousand, four hundred twenty-four".