385821 has 12 divisors (see below), whose sum is σ = 562848. Its totient is φ = 254664.

The previous prime is 385817. The next prime is 385831. The reversal of 385821 is 128583.

It is a happy number.

It is not a de Polignac number, because 385821 - 2² = 385817 is a prime.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (385811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1336 + ... + 1598.

It is an arithmetic number, because the mean of its divisors is an integer number (46904).

2³⁸⁵⁸²¹ is an apocalyptic number.

It is an amenable number.

385821 is a deficient number, since it is larger than the sum of its proper divisors (177027).

385821 is a wasteful number, since it uses less digits than its factorization.

385821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 432 (or 429 counting only the distinct ones).

The product of its digits is 1920, while the sum is 27.

The square root of 385821 is about 621.1449106288. The cubic root of 385821 is about 72.7995375932.

It can be divided in two parts, 38582 and 1, that added together give a palindrome (38583).

The spelling of 385821 in words is "three hundred eighty-five thousand, eight hundred twenty-one".