143821 has 2 divisors, whose sum is σ = 143822. Its totient is φ = 143820.

The previous prime is 143813. The next prime is 143827. The reversal of 143821 is 128341.

143821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 114921 + 28900 = 339^2 + 170^2 .

It is an emirp because it is prime and its reverse (128341) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 143821 - 2³ = 143813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (143827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 71910 + 71911.

It is an arithmetic number, because the mean of its divisors is an integer number (71911).

2¹⁴³⁸²¹ is an apocalyptic number.

It is an amenable number.

143821 is a deficient number, since it is larger than the sum of its proper divisors (1).

143821 is an equidigital number, since it uses as much as digits as its factorization.

143821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 192, while the sum is 19.

The square root of 143821 is about 379.2373926711. The cubic root of 143821 is about 52.3931006980.

The spelling of 143821 in words is "one hundred forty-three thousand, eight hundred twenty-one".