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81788313600 = 213335272113
BaseRepresentation
bin100110000101011110…
…1101010000000000000
321211002222010211002000
41030022331222000000
52320000302013400
6101323435224000
75623535123610
oct1141275520000
9254088124060
1081788313600
1131760409604
1213a268a8000
137935792846
143d5c48ca40
1521da4b9600
hex130af6a000

81788313600 has 672 divisors, whose sum is σ = 343565927040. Its totient is φ = 18685624320.

The previous prime is 81788313599. The next prime is 81788313601. The reversal of 81788313600 is 631388718.

81788313600 is a `hidden beast` number, since 8 + 1 + 7 + 8 + 8 + 31 + 3 + 600 = 666.

It is an interprime number because it is at equal distance from previous prime (81788313599) and next prime (81788313601).

It is a tau number, because it is divible by the number of its divisors (672).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (81788313601) 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 47 ways as a sum of consecutive naturals, for example, 38706144 + ... + 38708256.

It is an arithmetic number, because the mean of its divisors is an integer number (511258820).

Almost surely, 281788313600 is an apocalyptic number.

81788313600 is a gapful number since it is divisible by the number (80) 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 81788313600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (171782963520).

81788313600 is an abundant number, since it is smaller than the sum of its proper divisors (261777613440).

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

81788313600 is a wasteful number, since it uses less digits than its factorization.

81788313600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2165 (or 2130 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 45.

The spelling of 81788313600 in words is "eighty-one billion, seven hundred eighty-eight million, three hundred thirteen thousand, six hundred".