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BaseRepresentation
bin11010101101110001…
…010001111100010001
32202001010020011100121
4122231301101330101
5432221401240224
621102222550241
72033563004254
oct325561217421
982033204317
1028685180689
1111190044900
125686738381
132921b6bac9
14156198b09b
15b2d4acbe4

28685180689 has 27 divisors (see below), whose sum is σ = 32073632689. Its totient is φ = 25635389120.

The previous prime is 28685180681. The next prime is 28685180701. The reversal of 28685180689 is 98608158682.

The square root of 28685180689 is 169367.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 626250625 + 28058930064 = 25025^2 + 167508^2 .

It is not a de Polignac number, because 28685180689 - 23 = 28685180681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28685180681) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 165810207 + ... + 165810379.

Almost surely, 228685180689 is an apocalyptic number.

28685180689 is the 169367-th square number.

28685180689 is the 84684-th centered octagonal number.

It is an amenable number.

28685180689 is a deficient number, since it is larger than the sum of its proper divisors (3388452000).

28685180689 is an frugal number, since it uses more digits than its factorization.

28685180689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 546 (or 273 counting only the distinct ones).

The product of its (nonzero) digits is 13271040, while the sum is 61.

The spelling of 28685180689 in words is "twenty-eight billion, six hundred eighty-five million, one hundred eighty thousand, six hundred eighty-nine".