21253552000 has 256 divisors, whose sum is σ = 56112076800. Its totient is φ = 7983360000.

The previous prime is 21253551899. The next prime is 21253552007. The reversal of 21253552000 is 25535212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21253552007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 45903769 + ... + 45904231.

It is an arithmetic number, because the mean of its divisors is an integer number (219187800).

Almost surely, 2^21253552000 is an apocalyptic number.

21253552000 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 21253552000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28056038400).

21253552000 is an abundant number, since it is smaller than the sum of its proper divisors (34858524800).

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

21253552000 is a wasteful number, since it uses less digits than its factorization.

21253552000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 662 (or 640 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 25.

The spelling of 21253552000 in words is "twenty-one billion, two hundred fifty-three million, five hundred fifty-two thousand".