39855840 has 96 divisors (see below), whose sum is σ = 128532096. Its totient is φ = 10375680.

The previous prime is 39855839. The next prime is 39855869. The reversal of 39855840 is 4855893.

It is a tau number, because it is divible by the number of its divisors (96).

It is a junction number, because it is equal to n+sod(n) for n = 39855792 and 39855801.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19675 + ... + 21605.

It is an arithmetic number, because the mean of its divisors is an integer number (1338876).

Almost surely, 2^39855840 is an apocalyptic number.

39855840 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 39855840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (64266048).

39855840 is an abundant number, since it is smaller than the sum of its proper divisors (88676256).

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

39855840 is a wasteful number, since it uses less digits than its factorization.

39855840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1992 (or 1984 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 42.

The square root of 39855840 is about 6313.1481845431. The cubic root of 39855840 is about 341.5838445559.

The spelling of 39855840 in words is "thirty-nine million, eight hundred fifty-five thousand, eight hundred forty".