21765060800 has 336 divisors, whose sum is σ = 63133102080. Its totient is φ = 7230935040.

The previous prime is 21765060799. The next prime is 21765060803. The reversal of 21765060800 is 806056712.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is not an unprimeable number, because it can be changed into a prime (21765060803) 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 47 ways as a sum of consecutive naturals, for example, 91067081 + ... + 91067319.

Almost surely, 2^21765060800 is an apocalyptic number.

21765060800 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 21765060800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31566551040).

21765060800 is an abundant number, since it is smaller than the sum of its proper divisors (41368041280).

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

21765060800 is a wasteful number, since it uses less digits than its factorization.

21765060800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 488 (or 473 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 35.

The spelling of 21765060800 in words is "twenty-one billion, seven hundred sixty-five million, sixty thousand, eight hundred".