21152421344 has 24 divisors (see below), whose sum is σ = 42349660920. Its totient is φ = 10396951936.

The previous prime is 21152421341. The next prime is 21152421349. The reversal of 21152421344 is 44312425112.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21152421341) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5599919 + ... + 5603694.

It is an arithmetic number, because the mean of its divisors is an integer number (1764569205).

Almost surely, 2^21152421344 is an apocalyptic number.

It is an amenable number.

21152421344 is an abundant number, since it is smaller than the sum of its proper divisors (21197239576).

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

21152421344 is a wasteful number, since it uses less digits than its factorization.

21152421344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11203682 (or 11203674 counting only the distinct ones).

The product of its digits is 7680, while the sum is 29.

Adding to 21152421344 its reverse (44312425112), we get a palindrome (65464846456).

The spelling of 21152421344 in words is "twenty-one billion, one hundred fifty-two million, four hundred twenty-one thousand, three hundred forty-four".