399871 has 2 divisors, whose sum is σ = 399872. Its totient is φ = 399870.

The previous prime is 399853. The next prime is 399887. The reversal of 399871 is 178993.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 399871 - 2¹³ = 391679 is a prime.

It is a zygodrome in base 2.

It is a self number, because there is not a number n which added to its sum of digits gives 399871.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199935 + 199936.

It is an arithmetic number, because the mean of its divisors is an integer number (199936).

2³⁹⁹⁸⁷¹ is an apocalyptic number.

399871 is a deficient number, since it is larger than the sum of its proper divisors (1).

399871 is an equidigital number, since it uses as much as digits as its factorization.

399871 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13608, while the sum is 37.

The square root of 399871 is about 632.3535403554. The cubic root of 399871 is about 73.6727084535.

The spelling of 399871 in words is "three hundred ninety-nine thousand, eight hundred seventy-one".