395643840 has 224 divisors, whose sum is σ = 1341120000. Its totient is φ = 98537472.

The previous prime is 395643827. The next prime is 395643863. The reversal of 395643840 is 48346593.

It is a junction number, because it is equal to n+sod(n) for n = 395643792 and 395643801.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1988061 + ... + 1988259.

Almost surely, 2^395643840 is an apocalyptic number.

395643840 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 395643840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (670560000).

395643840 is an abundant number, since it is smaller than the sum of its proper divisors (945476160).

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

395643840 is a wasteful number, since it uses less digits than its factorization.

395643840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 347 (or 337 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 42.

The square root of 395643840 is about 19890.7978723831. The cubic root of 395643840 is about 734.1218259083.

The spelling of 395643840 in words is "three hundred ninety-five million, six hundred forty-three thousand, eight hundred forty".