285812921 has 2 divisors, whose sum is σ = 285812922. Its totient is φ = 285812920.

The previous prime is 285812869. The next prime is 285812929. The reversal of 285812921 is 129218582.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 220849321 + 64963600 = 14861^2 + 8060^2 .

It is a cyclic number.

It is not a de Polignac number, because 285812921 - 2¹⁸ = 285550777 is a prime.

It is a super-3 number, since 3×285812921³ (a number of 26 digits) contains 333 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (285812929) 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, 142906460 + 142906461.

It is an arithmetic number, because the mean of its divisors is an integer number (142906461).

Almost surely, 2^285812921 is an apocalyptic number.

It is an amenable number.

285812921 is a deficient number, since it is larger than the sum of its proper divisors (1).

285812921 is an equidigital number, since it uses as much as digits as its factorization.

285812921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23040, while the sum is 38.

The square root of 285812921 is about 16906.0025139002. The cubic root of 285812921 is about 658.7095392385.

The spelling of 285812921 in words is "two hundred eighty-five million, eight hundred twelve thousand, nine hundred twenty-one".