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BaseRepresentation
bin1010001101011…
…00001010001101
312222010221202020
411012230022031
5133410433241
612255320353
72056632531
oct506541215
9188127666
1085639821
1144383513
12248200b9
1314986467
14b533bc1
1577b9b66
hex51ac28d

85639821 has 16 divisors (see below), whose sum is σ = 120431040. Its totient is φ = 53982720.

The previous prime is 85639811. The next prime is 85639837. The reversal of 85639821 is 12893658.

It is not a de Polignac number, because 85639821 - 214 = 85623437 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85639811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36541 + ... + 38813.

It is an arithmetic number, because the mean of its divisors is an integer number (7526940).

Almost surely, 285639821 is an apocalyptic number.

It is an amenable number.

85639821 is a deficient number, since it is larger than the sum of its proper divisors (34791219).

85639821 is a wasteful number, since it uses less digits than its factorization.

85639821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2956.

The product of its digits is 103680, while the sum is 42.

The square root of 85639821 is about 9254.1785697057. The cubic root of 85639821 is about 440.7834200640.

The spelling of 85639821 in words is "eighty-five million, six hundred thirty-nine thousand, eight hundred twenty-one".