21254310720 has 336 divisors, whose sum is σ = 74750279760. Its totient is φ = 5541888000.

The previous prime is 21254310683. The next prime is 21254310733. The reversal of 21254310720 is 2701345212.

21254310720 is a `hidden beast` number, since 2 + 12 + 543 + 107 + 2 + 0 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 80568576 + 21173742144 = 8976^2 + 145512^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 25887910 + ... + 25888730.

Almost surely, 2^21254310720 is an apocalyptic number.

21254310720 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 21254310720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37375139880).

21254310720 is an abundant number, since it is smaller than the sum of its proper divisors (53495969040).

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

21254310720 is a wasteful number, since it uses less digits than its factorization.

21254310720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1034 (or 1021 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

Adding to 21254310720 its reverse (2701345212), we get a palindrome (23955655932).

The spelling of 21254310720 in words is "twenty-one billion, two hundred fifty-four million, three hundred ten thousand, seven hundred twenty".