21425556960 has 288 divisors, whose sum is σ = 79307478432. Its totient is φ = 5245992960.

The previous prime is 21425556953. The next prime is 21425557073. The reversal of 21425556960 is 6965552412.

21425556960 is a `hidden beast` number, since 2 + 1 + 4 + 2 + 5 + 556 + 96 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

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 47 ways as a sum of consecutive naturals, for example, 993007 + ... + 1014353.

It is an arithmetic number, because the mean of its divisors is an integer number (275373189).

Almost surely, 2^21425556960 is an apocalyptic number.

21425556960 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 21425556960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39653739216).

21425556960 is an abundant number, since it is smaller than the sum of its proper divisors (57881921472).

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

21425556960 is a wasteful number, since it uses less digits than its factorization.

21425556960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21426 (or 21415 counting only the distinct ones).

The product of its (nonzero) digits is 648000, while the sum is 45.

The spelling of 21425556960 in words is "twenty-one billion, four hundred twenty-five million, five hundred fifty-six thousand, nine hundred sixty".