21528954720 has 576 divisors, whose sum is σ = 95191649280. Its totient is φ = 4302802944.

The previous prime is 21528954697. The next prime is 21528954731. The reversal of 21528954720 is 2745982512.

21528954720 is a `hidden beast` number, since 2 + 1 + 5 + 2 + 89 + 547 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2485437 + ... + 2494083.

It is an arithmetic number, because the mean of its divisors is an integer number (165263280).

Almost surely, 2^21528954720 is an apocalyptic number.

21528954720 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 21528954720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47595824640).

21528954720 is an abundant number, since it is smaller than the sum of its proper divisors (73662694560).

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

21528954720 is a wasteful number, since it uses less digits than its factorization.

21528954720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8707 (or 8696 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 45.

The spelling of 21528954720 in words is "twenty-one billion, five hundred twenty-eight million, nine hundred fifty-four thousand, seven hundred twenty".