3939840 has 200 divisors, whose sum is σ = 14853960. Its totient is φ = 995328.

The previous prime is 3939839. The next prime is 3939841. The reversal of 3939840 is 489393.

It is an interprime number because it is at equal distance from previous prime (3939839) and next prime (3939841).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 3939795 and 3939804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3939841) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 207351 + ... + 207369.

Almost surely, 2^3939840 is an apocalyptic number.

3939840 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 3939840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7426980).

3939840 is an abundant number, since it is smaller than the sum of its proper divisors (10914120).

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

3939840 is an equidigital number, since it uses as much as digits as its factorization.

3939840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54 (or 29 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The square root of 3939840 is about 1984.9030203010. The cubic root of 3939840 is about 157.9402647658.

The spelling of 3939840 in words is "three million, nine hundred thirty-nine thousand, eight hundred forty".