164821 has 2 divisors, whose sum is σ = 164822. Its totient is φ = 164820.
The previous prime is 164809. The next prime is 164831. The reversal of 164821 is 128461.
164821 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., 119025 + 45796 = 345^2 + 214^2 .
It is an emirp because it is prime and its reverse (128461) is a distict prime.
It is a cyclic number.
It is not a de Polignac number, because 164821 - 25 = 164789 is a prime.
It is a Chen prime.
It is a zygodrome in base 4.
It is a junction number, because it is equal to n+sod(n) for n = 164792 and 164801.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (164831) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82410 + 82411.
It is an arithmetic number, because the mean of its divisors is an integer number (82411).
2164821 is an apocalyptic number.
It is an amenable number.
164821 is a deficient number, since it is larger than the sum of its proper divisors (1).
164821 is an equidigital number, since it uses as much as digits as its factorization.
164821 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 384, while the sum is 22.
The square root of 164821 is about 405.9815266733. The cubic root of 164821 is about 54.8282244008.
The spelling of 164821 in words is "one hundred sixty-four thousand, eight hundred twenty-one".
• e-mail: info -at- numbersaplenty.com • Privacy notice • done in 0.067 sec. • engine limits •