285389309 has 4 divisors (see below), whose sum is σ = 285575100. Its totient is φ = 285203520.

The previous prime is 285389263. The next prime is 285389333. The reversal of 285389309 is 903983582.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 132940900 + 152448409 = 11530^2 + 12347^2 .

It is a cyclic number.

It is not a de Polignac number, because 285389309 - 2²⁰ = 284340733 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (285389389) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 90572 + ... + 93669.

It is an arithmetic number, because the mean of its divisors is an integer number (71393775).

Almost surely, 2^285389309 is an apocalyptic number.

It is an amenable number.

285389309 is a deficient number, since it is larger than the sum of its proper divisors (185791).

285389309 is a wasteful number, since it uses less digits than its factorization.

285389309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185790.

The product of its (nonzero) digits is 466560, while the sum is 47.

The square root of 285389309 is about 16893.4694186837. The cubic root of 285389309 is about 658.3839471991.

The spelling of 285389309 in words is "two hundred eighty-five million, three hundred eighty-nine thousand, three hundred nine".