399890 has 8 divisors (see below), whose sum is σ = 719820. Its totient is φ = 159952.

The previous prime is 399887. The next prime is 399899. The reversal of 399890 is 98993.

It can be written as a sum of positive squares in 2 ways, for example, as 373321 + 26569 = 611^2 + 163^2 .

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

It is not an unprimeable number, because it can be changed into a prime (399899) 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 in 3 ways as a sum of consecutive naturals, for example, 19985 + ... + 20004.

2³⁹⁹⁸⁹⁰ is an apocalyptic number.

399890 is a deficient number, since it is larger than the sum of its proper divisors (319930).

399890 is a wasteful number, since it uses less digits than its factorization.

399890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39996.

The product of its (nonzero) digits is 17496, while the sum is 38.

The square root of 399890 is about 632.3685634185. The cubic root of 399890 is about 73.6738752958.

The spelling of 399890 in words is "three hundred ninety-nine thousand, eight hundred ninety".