287904289 has 4 divisors (see below), whose sum is σ = 295685524. Its totient is φ = 280123056.

The previous prime is 287904263. The next prime is 287904319. The reversal of 287904289 is 982409782.

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 177822225 + 110082064 = 13335^2 + 10492^2 .

It is a cyclic number.

It is not a de Polignac number, because 287904289 - 2¹⁹ = 287380001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (287904229) 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, 3890562 + ... + 3890635.

It is an arithmetic number, because the mean of its divisors is an integer number (73921381).

Almost surely, 2^287904289 is an apocalyptic number.

It is an amenable number.

287904289 is a deficient number, since it is larger than the sum of its proper divisors (7781235).

287904289 is an equidigital number, since it uses as much as digits as its factorization.

287904289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7781234.

The product of its (nonzero) digits is 580608, while the sum is 49.

The square root of 287904289 is about 16967.7426017723. The cubic root of 287904289 is about 660.3122864053.

The spelling of 287904289 in words is "two hundred eighty-seven million, nine hundred four thousand, two hundred eighty-nine".