131009 has 2 divisors, whose sum is σ = 131010. Its totient is φ = 131008.
The previous prime is 130987. The next prime is 131011. The reversal of 131009 is 900131.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 124609 + 6400 = 353^2 + 80^2 .
It is a cyclic number.
It is not a de Polignac number, because 131009 - 212 = 126913 is a prime.
Together with 131011, it forms a pair of twin primes.
It is a Chen prime.
It is equal to p12245 and since 131009 and 12245 have the same sum of digits, it is a Honaker prime.
It is a junction number, because it is equal to n+sod(n) for n = 130984 and 131002.
It is not a weakly prime, because it can be changed into another prime (131059) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65504 + 65505.
It is an arithmetic number, because the mean of its divisors is an integer number (65505).
2131009 is an apocalyptic number.
It is an amenable number.
131009 is a deficient number, since it is larger than the sum of its proper divisors (1).
131009 is an equidigital number, since it uses as much as digits as its factorization.
131009 is an evil number, because the sum of its binary digits is even.
The product of its (nonzero) digits is 27, while the sum is 14.
The square root of 131009 is about 361.9516542302. The cubic root of 131009 is about 50.7886938279.
The spelling of 131009 in words is "one hundred thirty-one thousand, nine".
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