71257 has 2 divisors, whose sum is σ = 71258. Its totient is φ = 71256.
The previous prime is 71249. The next prime is 71261. The reversal of 71257 is 75217.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 68121 + 3136 = 261^2 + 56^2 .
It is an emirp because it is prime and its reverse (75217) is a distict prime.
It is a cyclic number.
It is not a de Polignac number, because 71257 - 23 = 71249 is a prime.
It is a Chen prime.
It is not a weakly prime, because it can be changed into another prime (71237) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35628 + 35629.
It is an arithmetic number, because the mean of its divisors is an integer number (35629).
271257 is an apocalyptic number.
It is an amenable number.
71257 is a deficient number, since it is larger than the sum of its proper divisors (1).
71257 is an equidigital number, since it uses as much as digits as its factorization.
71257 is an evil number, because the sum of its binary digits is even.
The product of its digits is 490, while the sum is 22.
The square root of 71257 is about 266.9400681801. The cubic root of 71257 is about 41.4580793118.
The spelling of 71257 in words is "seventy-one thousand, two hundred fifty-seven".
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