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21768155136 = 212347213103
BaseRepresentation
bin10100010001011110…
…111011000000000000
32002012001121212010000
4110101132323000000
5324040121431021
614000011040000
71400302160100
oct242136730000
962161555100
1021768155136
119260613162
124276140000
13208bac8090
1410a706d200
158760d3b26
hex5117bb000

21768155136 has 780 divisors, whose sum is σ = 82254284112. Its totient is φ = 5685313536.

The previous prime is 21768155111. The next prime is 21768155137. The reversal of 21768155136 is 63155186712.

21768155136 is a `hidden beast` number, since 2 + 1 + 7 + 68 + 1 + 551 + 36 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 21768155091 and 21768155100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21768155137) 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 59 ways as a sum of consecutive naturals, for example, 211341261 + ... + 211341363.

Almost surely, 221768155136 is an apocalyptic number.

21768155136 is a gapful number since it is divisible by the number (26) 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 21768155136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41127142056).

21768155136 is an abundant number, since it is smaller than the sum of its proper divisors (60486128976).

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

21768155136 is a wasteful number, since it uses less digits than its factorization.

21768155136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166 (or 128 counting only the distinct ones).

The product of its digits is 302400, while the sum is 45.

The spelling of 21768155136 in words is "twenty-one billion, seven hundred sixty-eight million, one hundred fifty-five thousand, one hundred thirty-six".