399642 has 16 divisors (see below), whose sum is σ = 818400. Its totient is φ = 130032.

The previous prime is 399617. The next prime is 399643. The reversal of 399642 is 246993.

It is not an unprimeable number, because it can be changed into a prime (399643) by changing a digit.

399642 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 517 + ... + 1032.

It is an arithmetic number, because the mean of its divisors is an integer number (51150).

2³⁹⁹⁶⁴² is an apocalyptic number.

399642 is an abundant number, since it is smaller than the sum of its proper divisors (418758).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

399642 is a wasteful number, since it uses less digits than its factorization.

399642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1597.

The product of its digits is 11664, while the sum is 33.

The square root of 399642 is about 632.1724448281. The cubic root of 399642 is about 73.6586420238.

The spelling of 399642 in words is "three hundred ninety-nine thousand, six hundred forty-two".