21908734848 has 640 divisors, whose sum is σ = 87582781440. Its totient is φ = 5250355200.

The previous prime is 21908734831. The next prime is 21908734889. The reversal of 21908734848 is 84843780912.

It is a happy number.

21908734848 is a `hidden beast` number, since 2 + 1 + 90 + 8 + 73 + 484 + 8 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 21908734794 and 21908734803.

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, 10377313 + ... + 10379423.

It is an arithmetic number, because the mean of its divisors is an integer number (136848096).

Almost surely, 2^21908734848 is an apocalyptic number.

21908734848 is a gapful number since it is divisible by the number (28) 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 21908734848, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43791390720).

21908734848 is an abundant number, since it is smaller than the sum of its proper divisors (65674046592).

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

21908734848 is a wasteful number, since it uses less digits than its factorization.

21908734848 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2168 (or 2147 counting only the distinct ones).

The product of its (nonzero) digits is 3096576, while the sum is 54.

The spelling of 21908734848 in words is "twenty-one billion, nine hundred eight million, seven hundred thirty-four thousand, eight hundred forty-eight".