21250559520 has 384 divisors, whose sum is σ = 77546004480. Its totient is φ = 5429099520.

The previous prime is 21250559503. The next prime is 21250559549. The reversal of 21250559520 is 2595505212.

21250559520 is a `hidden beast` number, since 2 + 1 + 2 + 50 + 559 + 52 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 14328699 + ... + 14330181.

It is an arithmetic number, because the mean of its divisors is an integer number (201942720).

Almost surely, 2^21250559520 is an apocalyptic number.

21250559520 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 21250559520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38773002240).

21250559520 is an abundant number, since it is smaller than the sum of its proper divisors (56295444960).

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

21250559520 is a wasteful number, since it uses less digits than its factorization.

21250559520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1645 (or 1631 counting only the distinct ones).

The product of its (nonzero) digits is 45000, while the sum is 36.

The spelling of 21250559520 in words is "twenty-one billion, two hundred fifty million, five hundred fifty-nine thousand, five hundred twenty".