21431224320 has 192 divisors, whose sum is σ = 74797369920. Its totient is φ = 5195366400.

The previous prime is 21431224307. The next prime is 21431224337. The reversal of 21431224320 is 2342213412.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (192).

It is a Harshad number since it is a multiple of its sum of digits (24).

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, 306210 + ... + 369630.

It is an arithmetic number, because the mean of its divisors is an integer number (389569635).

Almost surely, 2^21431224320 is an apocalyptic number.

21431224320 is a gapful number since it is divisible by the number (20) 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 21431224320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37398684960).

21431224320 is an abundant number, since it is smaller than the sum of its proper divisors (53366145600).

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

21431224320 is a wasteful number, since it uses less digits than its factorization.

21431224320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63462 (or 63442 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 24.

Adding to 21431224320 its reverse (2342213412), we get a palindrome (23773437732).

The spelling of 21431224320 in words is "twenty-one billion, four hundred thirty-one million, two hundred twenty-four thousand, three hundred twenty".