162821 has 2 divisors, whose sum is σ = 162822. Its totient is φ = 162820.

The previous prime is 162791. The next prime is 162823. The reversal of 162821 is 128261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 136900 + 25921 = 370^2 + 161^2 .

It is a cyclic number.

It is not a de Polignac number, because 162821 - 2¹⁴ = 146437 is a prime.

It is a Sophie Germain prime.

Together with 162823, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a plaindrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 162793 and 162802.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (162823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 81410 + 81411.

It is an arithmetic number, because the mean of its divisors is an integer number (81411).

2¹⁶²⁸²¹ is an apocalyptic number.

It is an amenable number.

162821 is a deficient number, since it is larger than the sum of its proper divisors (1).

162821 is an equidigital number, since it uses as much as digits as its factorization.

162821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 192, while the sum is 20.

The square root of 162821 is about 403.5108424813. The cubic root of 162821 is about 54.6055525310.

The spelling of 162821 in words is "one hundred sixty-two thousand, eight hundred twenty-one".