825421 has 2 divisors, whose sum is σ = 825422. Its totient is φ = 825420.

The previous prime is 825413. The next prime is 825439. The reversal of 825421 is 124528.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 741321 + 84100 = 861^2 + 290^2 .

It is a cyclic number.

It is not a de Polignac number, because 825421 - 2³ = 825413 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 825392 and 825401.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (825491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 412710 + 412711.

It is an arithmetic number, because the mean of its divisors is an integer number (412711).

2⁸²⁵⁴²¹ is an apocalyptic number.

It is an amenable number.

825421 is a deficient number, since it is larger than the sum of its proper divisors (1).

825421 is an equidigital number, since it uses as much as digits as its factorization.

825421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 640, while the sum is 22.

The square root of 825421 is about 908.5268295433. The cubic root of 825421 is about 93.8048236374.

Adding to 825421 its reverse (124528), we get a palindrome (949949).

The spelling of 825421 in words is "eight hundred twenty-five thousand, four hundred twenty-one".