399626 has 4 divisors (see below), whose sum is σ = 599442. Its totient is φ = 199812.

The previous prime is 399617. The next prime is 399643. The reversal of 399626 is 626993.

399626 is nontrivially palindromic in base 5.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 626993 = 59 ⋅10627.

It can be written as a sum of positive squares in only one way, i.e., 201601 + 198025 = 449^2 + 445^2 .

It is an unprimeable 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 as a sum of consecutive naturals, namely, 99905 + ... + 99908.

2³⁹⁹⁶²⁶ is an apocalyptic number.

399626 is a deficient number, since it is larger than the sum of its proper divisors (199816).

399626 is a wasteful number, since it uses less digits than its factorization.

399626 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199815.

The product of its digits is 17496, while the sum is 35.

The square root of 399626 is about 632.1597899266. The cubic root of 399626 is about 73.6576590157.

The spelling of 399626 in words is "three hundred ninety-nine thousand, six hundred twenty-six".