238821 has 8 divisors (see below), whose sum is σ = 347424. Its totient is φ = 144720.

The previous prime is 238801. The next prime is 238829. The reversal of 238821 is 128832.

Added to its reverse (128832) it gives a triangular number (367653 = T₈₅₇).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 238821 - 2⁵ = 238789 is a prime.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 238791 and 238800.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 238821.

It is not an unprimeable number, because it can be changed into a prime (238829) 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, 3586 + ... + 3651.

It is an arithmetic number, because the mean of its divisors is an integer number (43428).

2²³⁸⁸²¹ is an apocalyptic number.

It is an amenable number.

238821 is a deficient number, since it is larger than the sum of its proper divisors (108603).

238821 is a wasteful number, since it uses less digits than its factorization.

238821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7251.

The product of its digits is 768, while the sum is 24.

The square root of 238821 is about 488.6931552621. The cubic root of 238821 is about 62.0427211632.

Adding to 238821 its reverse (128832), we get a triangular number (367653 = T₈₅₇).

The spelling of 238821 in words is "two hundred thirty-eight thousand, eight hundred twenty-one".