20688155136 has 320 divisors, whose sum is σ = 68629714560. Its totient is φ = 6098042880.

The previous prime is 20688155101. The next prime is 20688155143. The reversal of 20688155136 is 63155188602.

20688155136 is a `hidden beast` number, since 2 + 0 + 68 + 8 + 1 + 551 + 36 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 20688155091 and 20688155100.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5624530 + ... + 5628206.

It is an arithmetic number, because the mean of its divisors is an integer number (214467858).

Almost surely, 2^20688155136 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 20688155136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34314857280).

20688155136 is an abundant number, since it is smaller than the sum of its proper divisors (47941559424).

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

20688155136 is a wasteful number, since it uses less digits than its factorization.

20688155136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3752 (or 3730 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 45.

The spelling of 20688155136 in words is "twenty billion, six hundred eighty-eight million, one hundred fifty-five thousand, one hundred thirty-six".