3942840 has 128 divisors (see below), whose sum is σ = 13478400. Its totient is φ = 913920.

The previous prime is 3942839. The next prime is 3942871. The reversal of 3942840 is 482493.

It is a happy number.

3942840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 3942798 and 3942807.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 38229 + ... + 38331.

It is an arithmetic number, because the mean of its divisors is an integer number (105300).

Almost surely, 2^3942840 is an apocalyptic number.

3942840 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3942840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6739200).

3942840 is an abundant number, since it is smaller than the sum of its proper divisors (9535560).

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

3942840 is a wasteful number, since it uses less digits than its factorization.

3942840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157 (or 153 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 30.

The square root of 3942840 is about 1985.6585809247. The cubic root of 3942840 is about 157.9803425846.

The spelling of 3942840 in words is "three million, nine hundred forty-two thousand, eight hundred forty".