21059280 has 120 divisors (see below), whose sum is σ = 77182560. Its totient is φ = 5103360.

The previous prime is 21059273. The next prime is 21059309. The reversal of 21059280 is 8295012.

It is a tau number, because it is divible by the number of its divisors (120).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6591 + ... + 9249.

It is an arithmetic number, because the mean of its divisors is an integer number (643188).

Almost surely, 2^21059280 is an apocalyptic number.

21059280 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 21059280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38591280).

21059280 is an abundant number, since it is smaller than the sum of its proper divisors (56123280).

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

21059280 is a wasteful number, since it uses less digits than its factorization.

21059280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2689 (or 2680 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 21059280 is about 4589.0391151090. The cubic root of 21059280 is about 276.1517753750.

The spelling of 21059280 in words is "twenty-one million, fifty-nine thousand, two hundred eighty".