21323401424 has 80 divisors (see below), whose sum is σ = 45857898240. Its totient is φ = 9543329280.

The previous prime is 21323401391. The next prime is 21323401459. The reversal of 21323401424 is 42410432312.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a junction number, because it is equal to n+sod(n) for n = 21323401393 and 21323401402.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1055579 + ... + 1075589.

It is an arithmetic number, because the mean of its divisors is an integer number (573223728).

Almost surely, 2^21323401424 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21323401424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22928949120).

21323401424 is an abundant number, since it is smaller than the sum of its proper divisors (24534496816).

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

21323401424 is a wasteful number, since it uses less digits than its factorization.

21323401424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20188 (or 20182 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 26.

Adding to 21323401424 its reverse (42410432312), we get a palindrome (63733833736).

The spelling of 21323401424 in words is "twenty-one billion, three hundred twenty-three million, four hundred one thousand, four hundred twenty-four".