399878 has 8 divisors (see below), whose sum is σ = 625968. Its totient is φ = 191224.

The previous prime is 399871. The next prime is 399887. The reversal of 399878 is 878993.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399871) by changing a digit.

399878 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 in 3 ways as a sum of consecutive naturals, for example, 4301 + ... + 4392.

It is an arithmetic number, because the mean of its divisors is an integer number (78246).

2³⁹⁹⁸⁷⁸ is an apocalyptic number.

399878 is a deficient number, since it is larger than the sum of its proper divisors (226090).

399878 is a wasteful number, since it uses less digits than its factorization.

399878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8718.

The product of its digits is 108864, while the sum is 44.

The square root of 399878 is about 632.3590752096. The cubic root of 399878 is about 73.6731383471.

The spelling of 399878 in words is "three hundred ninety-nine thousand, eight hundred seventy-eight".