39971 has 2 divisors, whose sum is σ = 39972. Its totient is φ = 39970.

The previous prime is 39953. The next prime is 39979. The reversal of 39971 is 17993.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-39971 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (39979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19985 + 19986.

It is an arithmetic number, because the mean of its divisors is an integer number (19986).

2³⁹⁹⁷¹ is an apocalyptic number.

39971 is a deficient number, since it is larger than the sum of its proper divisors (1).

39971 is an equidigital number, since it uses as much as digits as its factorization.

39971 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1701, while the sum is 29.

The square root of 39971 is about 199.9274868546. The cubic root of 39971 is about 34.1912520516.

Adding to 39971 its sum of digits (29), we get a square (40000 = 200²).

The spelling of 39971 in words is "thirty-nine thousand, nine hundred seventy-one".