400642 has 8 divisors (see below), whose sum is σ = 655632. Its totient is φ = 182100.

The previous prime is 400619. The next prime is 400643. The reversal of 400642 is 246004.

400642 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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 (400643) by changing a digit.

400642 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, 9084 + ... + 9127.

It is an arithmetic number, because the mean of its divisors is an integer number (81954).

2⁴⁰⁰⁶⁴² is an apocalyptic number.

400642 is a deficient number, since it is larger than the sum of its proper divisors (254990).

400642 is a wasteful number, since it uses less digits than its factorization.

400642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18224.

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 400642 is about 632.9628741087. The cubic root of 400642 is about 73.7200280394.

Adding to 400642 its reverse (246004), we get a palindrome (646646).

The spelling of 400642 in words is "four hundred thousand, six hundred forty-two".