21768963840 has 720 divisors, whose sum is σ = 86757302016. Its totient is φ = 5175705600.

The previous prime is 21768963833. The next prime is 21768963901. The reversal of 21768963840 is 4836986712.

21768963840 is a `hidden beast` number, since 2 + 176 + 8 + 96 + 384 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 41782780 + ... + 41783300.

Almost surely, 2^21768963840 is an apocalyptic number.

21768963840 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 21768963840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43378651008).

21768963840 is an abundant number, since it is smaller than the sum of its proper divisors (64988338176).

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

21768963840 is a wasteful number, since it uses less digits than its factorization.

21768963840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 598 (or 575 counting only the distinct ones).

The product of its (nonzero) digits is 3483648, while the sum is 54.

The spelling of 21768963840 in words is "twenty-one billion, seven hundred sixty-eight million, nine hundred sixty-three thousand, eight hundred forty".