395809840 has 40 divisors (see below), whose sum is σ = 941667408. Its totient is φ = 154640640.

The previous prime is 395809837. The next prime is 395809849. The reversal of 395809840 is 48908593.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (395809849) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 54091 + ... + 60970.

Almost surely, 2^395809840 is an apocalyptic number.

It is an amenable number.

395809840 is an abundant number, since it is smaller than the sum of its proper divisors (545857568).

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

395809840 is a wasteful number, since it uses less digits than its factorization.

395809840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115117 (or 115111 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 46.

The square root of 395809840 is about 19894.9702186256. The cubic root of 395809840 is about 734.2244832070.

The spelling of 395809840 in words is "three hundred ninety-five million, eight hundred nine thousand, eight hundred forty".