395818921 has 4 divisors (see below), whose sum is σ = 401241172. Its totient is φ = 390396672.

The previous prime is 395818897. The next prime is 395818967. The reversal of 395818921 is 129818593.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 129818593 = 269 ⋅482597.

It can be written as a sum of positive squares in 2 ways, for example, as 99600400 + 296218521 = 9980^2 + 17211^2 .

It is a cyclic number.

It is not a de Polignac number, because 395818921 - 2⁵ = 395818889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (395818981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2711016 + ... + 2711161.

It is an arithmetic number, because the mean of its divisors is an integer number (100310293).

Almost surely, 2^395818921 is an apocalyptic number.

It is an amenable number.

395818921 is a deficient number, since it is larger than the sum of its proper divisors (5422251).

395818921 is an equidigital number, since it uses as much as digits as its factorization.

395818921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5422250.

The product of its digits is 155520, while the sum is 46.

The square root of 395818921 is about 19895.1984408299. The cubic root of 395818921 is about 734.2300982278.

The spelling of 395818921 in words is "three hundred ninety-five million, eight hundred eighteen thousand, nine hundred twenty-one".