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20728568 = 237252879
BaseRepresentation
bin100111100010…
…0101011111000
31110000010020202
41033010223320
520301303233
62020141332
7341122100
oct117045370
943003222
1020728568
1110778753
126b37848
1343a9c33
142a78200
151c46be8
hex13c4af8

20728568 has 24 divisors (see below), whose sum is σ = 45212400. Its totient is φ = 8883504.

The previous prime is 20728549. The next prime is 20728571. The reversal of 20728568 is 86582702.

It is a congruent number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 26048 + ... + 26831.

It is an arithmetic number, because the mean of its divisors is an integer number (1883850).

Almost surely, 220728568 is an apocalyptic number.

20728568 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

20728568 is an abundant number, since it is smaller than the sum of its proper divisors (24483832).

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

20728568 is a wasteful number, since it uses less digits than its factorization.

20728568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52899 (or 52888 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 38.

The square root of 20728568 is about 4552.8637141913. The cubic root of 20728568 is about 274.6985920830.

The spelling of 20728568 in words is "twenty million, seven hundred twenty-eight thousand, five hundred sixty-eight".

Divisors: 1 2 4 7 8 14 28 49 56 98 196 392 52879 105758 211516 370153 423032 740306 1480612 2591071 2961224 5182142 10364284 20728568