8400042 has 48 divisors (see below), whose sum is σ = 20978880. Its totient is φ = 2379456.

The previous prime is 8400031. The next prime is 8400043. The reversal of 8400042 is 2400048.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 8399988 and 8400024.

It is not an unprimeable number, because it can be changed into a prime (8400043) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20334 + ... + 20742.

It is an arithmetic number, because the mean of its divisors is an integer number (437060).

Almost surely, 2^8400042 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8400042, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10489440).

8400042 is an abundant number, since it is smaller than the sum of its proper divisors (12578838).

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

8400042 is a wasteful number, since it uses less digits than its factorization.

8400042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 587 (or 584 counting only the distinct ones).

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

The square root of 8400042 is about 2898.2825949172. The cubic root of 8400042 is about 203.2796101612.

The spelling of 8400042 in words is "eight million, four hundred thousand, forty-two".