1385821 has 4 divisors (see below), whose sum is σ = 1399644. Its totient is φ = 1372000.

The previous prime is 1385809. The next prime is 1385827. The reversal of 1385821 is 1285831.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 881721 + 504100 = 939^2 + 710^2 .

It is a cyclic number.

It is not a de Polignac number, because 1385821 - 2⁷ = 1385693 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1385821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1385827) 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 3 ways as a sum of consecutive naturals, for example, 6760 + ... + 6961.

It is an arithmetic number, because the mean of its divisors is an integer number (349911).

2^1385821 is an apocalyptic number.

It is an amenable number.

1385821 is a deficient number, since it is larger than the sum of its proper divisors (13823).

1385821 is a wasteful number, since it uses less digits than its factorization.

1385821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13822.

The product of its digits is 1920, while the sum is 28.

The square root of 1385821 is about 1177.2089873935. The cubic root of 1385821 is about 111.4899479499.

The spelling of 1385821 in words is "one million, three hundred eighty-five thousand, eight hundred twenty-one".