400842 has 32 divisors (see below), whose sum is σ = 960960. Its totient is φ = 123120.

The previous prime is 400837. The next prime is 400849. The reversal of 400842 is 248004.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (400849) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 417 + ... + 987.

It is an arithmetic number, because the mean of its divisors is an integer number (30030).

2⁴⁰⁰⁸⁴² is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 400842, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (480480).

400842 is an abundant number, since it is smaller than the sum of its proper divisors (560118).

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

400842 is a wasteful number, since it uses less digits than its factorization.

400842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 595 (or 589 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The square root of 400842 is about 633.1208415461. The cubic root of 400842 is about 73.7322929816.

Adding to 400842 its reverse (248004), we get a palindrome (648846).

The spelling of 400842 in words is "four hundred thousand, eight hundred forty-two".