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78820 = 2257563
BaseRepresentation
bin10011001111100100
311000010021
4103033210
510010240
61404524
7445540
oct231744
9130107
1078820
1154245
1239744
1329b51
1420a20
151854a
hex133e4

78820 has 24 divisors (see below), whose sum is σ = 189504. Its totient is φ = 26976.

The previous prime is 78809. The next prime is 78823. The reversal of 78820 is 2887.

78820 is nontrivially palindromic in base 11.

It is not an unprimeable number, because it can be changed into a prime (78823) by changing a digit.

78820 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 142 + ... + 421.

It is an arithmetic number, because the mean of its divisors is an integer number (7896).

278820 is an apocalyptic number.

78820 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

78820 is an abundant number, since it is smaller than the sum of its proper divisors (110684).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94752).

78820 is a wasteful number, since it uses less digits than its factorization.

78820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 579 (or 577 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 78820 is about 280.7489982173. The cubic root of 78820 is about 42.8757908265.

It can be divided in two parts, 788 and 20, that added together give a palindrome (808).

The spelling of 78820 in words is "seventy-eight thousand, eight hundred twenty".

Divisors: 1 2 4 5 7 10 14 20 28 35 70 140 563 1126 2252 2815 3941 5630 7882 11260 15764 19705 39410 78820