285421 has 2 divisors, whose sum is σ = 285422. Its totient is φ = 285420.

The previous prime is 285377. The next prime is 285433. The reversal of 285421 is 124582.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 212521 + 72900 = 461^2 + 270^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-285421 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 285392 and 285401.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (285451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 142710 + 142711.

It is an arithmetic number, because the mean of its divisors is an integer number (142711).

2²⁸⁵⁴²¹ is an apocalyptic number.

It is an amenable number.

285421 is a deficient number, since it is larger than the sum of its proper divisors (1).

285421 is an equidigital number, since it uses as much as digits as its factorization.

285421 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 285421 is about 534.2480697204. The cubic root of 285421 is about 65.8408316336.

The spelling of 285421 in words is "two hundred eighty-five thousand, four hundred twenty-one".