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81031 is a prime number
BaseRepresentation
bin10011110010000111
311010011011
4103302013
510043111
61423051
7455146
oct236207
9133134
1081031
1155975
123aa87
132ab62
142175d
1519021
hex13c87

81031 has 2 divisors, whose sum is σ = 81032. Its totient is φ = 81030.

The previous prime is 81023. The next prime is 81041. The reversal of 81031 is 13018.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81031 - 23 = 81023 is a prime.

It is a super-2 number, since 2×810312 = 13132045922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40515 + 40516.

It is an arithmetic number, because the mean of its divisors is an integer number (40516).

281031 is an apocalyptic number.

81031 is a deficient number, since it is larger than the sum of its proper divisors (1).

81031 is an equidigital number, since it uses as much as digits as its factorization.

81031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 81031 is about 284.6594456539. The cubic root of 81031 is about 43.2730061258.

Subtracting from 81031 its sum of digits (13), we obtain a palindrome (81018).

Adding to 81031 its reverse (13018), we get a palindrome (94049).

It can be divided in two parts, 810 and 31, that added together give a square (841 = 292).

The spelling of 81031 in words is "eighty-one thousand, thirty-one".