285009861 has 12 divisors (see below), whose sum is σ = 401068032. Its totient is φ = 180005544.

The previous prime is 285009847. The next prime is 285009863. The reversal of 285009861 is 168900582.

It is not a de Polignac number, because 285009861 - 2²⁵ = 251455429 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (285009863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 130501 + ... + 132666.

It is an arithmetic number, because the mean of its divisors is an integer number (33422336).

Almost surely, 2^285009861 is an apocalyptic number.

It is an amenable number.

285009861 is a deficient number, since it is larger than the sum of its proper divisors (116058171).

285009861 is a wasteful number, since it uses less digits than its factorization.

285009861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263208 (or 263189 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 39.

The square root of 285009861 is about 16882.2350712221. The cubic root of 285009861 is about 658.0920263438.

The spelling of 285009861 in words is "two hundred eighty-five million, nine thousand, eight hundred sixty-one".