399242 has 4 divisors (see below), whose sum is σ = 598866. Its totient is φ = 199620.

The previous prime is 399241. The next prime is 399263. The reversal of 399242 is 242993.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 242993 = 43 ⋅5651.

It can be written as a sum of positive squares in only one way, i.e., 373321 + 25921 = 611^2 + 161^2 .

It is not an unprimeable number, because it can be changed into a prime (399241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99809 + ... + 99812.

2³⁹⁹²⁴² is an apocalyptic number.

399242 is a deficient number, since it is larger than the sum of its proper divisors (199624).

399242 is a wasteful number, since it uses less digits than its factorization.

399242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199623.

The product of its digits is 3888, while the sum is 29.

The square root of 399242 is about 631.8559962523. The cubic root of 399242 is about 73.6340589451.

The spelling of 399242 in words is "three hundred ninety-nine thousand, two hundred forty-two".