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85871521 is a prime number
BaseRepresentation
bin1010001111001…
…00101110100001
312222120201120201
411013210232201
5133440342041
612304305201
72061616201
oct507445641
9188521521
1085871521
11445215aa
1224912201
1314a37a68
14b594401
157813631
hex51e4ba1

85871521 has 2 divisors, whose sum is σ = 85871522. Its totient is φ = 85871520.

The previous prime is 85871503. The next prime is 85871537. The reversal of 85871521 is 12517858.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 79566400 + 6305121 = 8920^2 + 2511^2 .

It is a cyclic number.

It is not a de Polignac number, because 85871521 - 223 = 77482913 is a prime.

It is equal to p4991428 and since 85871521 and 4991428 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (85871921) 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 as a sum of consecutive naturals, namely, 42935760 + 42935761.

It is an arithmetic number, because the mean of its divisors is an integer number (42935761).

Almost surely, 285871521 is an apocalyptic number.

It is an amenable number.

85871521 is a deficient number, since it is larger than the sum of its proper divisors (1).

85871521 is an equidigital number, since it uses as much as digits as its factorization.

85871521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 22400, while the sum is 37.

The square root of 85871521 is about 9266.6887829472. The cubic root of 85871521 is about 441.1805777998.

It can be divided in two parts, 858715 and 21, that multiplied together give a triangular number (18033015 = T6005).

The spelling of 85871521 in words is "eighty-five million, eight hundred seventy-one thousand, five hundred twenty-one".