21501768000 has 448 divisors, whose sum is σ = 76059060480. Its totient is φ = 5336064000.

The previous prime is 21501767953. The next prime is 21501768007. The reversal of 21501768000 is 86710512.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21501768007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 27815614 + ... + 27816386.

Almost surely, 2^21501768000 is an apocalyptic number.

21501768000 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 21501768000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38029530240).

21501768000 is an abundant number, since it is smaller than the sum of its proper divisors (54557292480).

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

21501768000 is a wasteful number, since it uses less digits than its factorization.

21501768000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 883 (or 863 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 30.

The spelling of 21501768000 in words is "twenty-one billion, five hundred one million, seven hundred sixty-eight thousand".