238721 has 8 divisors (see below), whose sum is σ = 277440. Its totient is φ = 201168.

The previous prime is 238709. The next prime is 238723. The reversal of 238721 is 127832.

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

It is a cyclic number.

It is not a de Polignac number, because 238721 - 2⁶ = 238657 is a prime.

It is an Ulam number.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 238721.

It is not an unprimeable number, because it can be changed into a prime (238723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 215 + ... + 723.

It is an arithmetic number, because the mean of its divisors is an integer number (34680).

2²³⁸⁷²¹ is an apocalyptic number.

It is an amenable number.

238721 is a deficient number, since it is larger than the sum of its proper divisors (38719).

238721 is an equidigital number, since it uses as much as digits as its factorization.

238721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 583.

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

The square root of 238721 is about 488.5908308595. The cubic root of 238721 is about 62.0340603694.

Subtracting from 238721 its reverse (127832), we obtain a square (110889 = 333²).

It can be divided in two parts, 238 and 721, that added together give a palindrome (959).

The spelling of 238721 in words is "two hundred thirty-eight thousand, seven hundred twenty-one".