378221 has 4 divisors (see below), whose sum is σ = 379452. Its totient is φ = 376992.

The previous prime is 378193. The next prime is 378223. The reversal of 378221 is 122873.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 4900 + 373321 = 70^2 + 611^2 .

It is a cyclic number.

It is not a de Polignac number, because 378221 - 2¹⁰ = 377197 is a prime.

It is a super-2 number, since 2×378221² = 286102249682, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (378223) 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, 305 + ... + 921.

It is an arithmetic number, because the mean of its divisors is an integer number (94863).

2³⁷⁸²²¹ is an apocalyptic number.

It is an amenable number.

378221 is a deficient number, since it is larger than the sum of its proper divisors (1231).

378221 is an equidigital number, since it uses as much as digits as its factorization.

378221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1230.

The product of its digits is 672, while the sum is 23.

The square root of 378221 is about 614.9967479589. The cubic root of 378221 is about 72.3183562234.

It can be divided in two parts, 378 and 221, that multiplied together give a palindrome (83538).

The spelling of 378221 in words is "three hundred seventy-eight thousand, two hundred twenty-one".