21259038528 has 336 divisors, whose sum is σ = 75355338240. Its totient is φ = 5580029952.

The previous prime is 21259038503. The next prime is 21259038551. The reversal of 21259038528 is 82583095212.

21259038528 is a `hidden beast` number, since 2 + 1 + 2 + 5 + 90 + 38 + 528 = 666.

It is a tau number, because it is divible by the number of its divisors (336).

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, 12526576 + ... + 12528272.

It is an arithmetic number, because the mean of its divisors is an integer number (224271840).

Almost surely, 2^21259038528 is an apocalyptic number.

21259038528 is a gapful number since it is divisible by the number (28) 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 21259038528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37677669120).

21259038528 is an abundant number, since it is smaller than the sum of its proper divisors (54096299712).

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

21259038528 is a wasteful number, since it uses less digits than its factorization.

21259038528 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1974 (or 1961 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 45.

The spelling of 21259038528 in words is "twenty-one billion, two hundred fifty-nine million, thirty-eight thousand, five hundred twenty-eight".