3931 has 2 divisors, whose sum is σ = 3932. Its totient is φ = 3930.
The previous prime is 3929. The next prime is 3943. The reversal of 3931 is 1393.
It is a happy number.
It is a weak prime.
It is a cyclic number.
It is not a de Polignac number, because 3931 - 21 = 3929 is a prime.
It is a super-2 number, since 2×39312 = 30905522, which contains 22 as substring.
Together with 3929, it forms a pair of twin primes.
3931 is a lucky number.
It is a plaindrome in base 12.
It is a nialpdrome in base 8.
It is not a weakly prime, because it can be changed into another prime (3911) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1965 + 1966.
It is an arithmetic number, because the mean of its divisors is an integer number (1966).
3931 is a deficient number, since it is larger than the sum of its proper divisors (1).
3931 is an equidigital number, since it uses as much as digits as its factorization.
3931 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 81, while the sum is 16.
The square root of 3931 is about 62.6976873577. The cubic root of 3931 is about 15.7822050365.
The spelling of 3931 in words is "three thousand, nine hundred thirty-one".
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