20908238688 has 144 divisors (see below), whose sum is σ = 62970276096. Its totient is φ = 6566757120.

The previous prime is 20908238669. The next prime is 20908238719. The reversal of 20908238688 is 88683280902.

20908238688 is a `hidden beast` number, since 20 + 90 + 82 + 386 + 88 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×20908238688² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 420253 + ... + 467363.

It is an arithmetic number, because the mean of its divisors is an integer number (437293584).

Almost surely, 2^20908238688 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20908238688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31485138048).

20908238688 is an abundant number, since it is smaller than the sum of its proper divisors (42062037408).

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

20908238688 is a wasteful number, since it uses less digits than its factorization.

20908238688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47217 (or 47206 counting only the distinct ones).

The product of its (nonzero) digits is 2654208, while the sum is 54.

The spelling of 20908238688 in words is "twenty billion, nine hundred eight million, two hundred thirty-eight thousand, six hundred eighty-eight".