21301280 has 288 divisors, whose sum is σ = 72394560. Its totient is φ = 5806080.

The previous prime is 21301279. The next prime is 21301321. The reversal of 21301280 is 8210312.

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, 1121111 + ... + 1121129.

It is an arithmetic number, because the mean of its divisors is an integer number (251370).

Almost surely, 2^21301280 is an apocalyptic number.

21301280 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 21301280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36197280).

21301280 is an abundant number, since it is smaller than the sum of its proper divisors (51093280).

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

21301280 is a wasteful number, since it uses less digits than its factorization.

21301280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72 (or 57 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 21301280 is about 4615.3309740473. The cubic root of 21301280 is about 277.2055367394.

Adding to 21301280 its reverse (8210312), we get a palindrome (29511592).

The spelling of 21301280 in words is "twenty-one million, three hundred one thousand, two hundred eighty".