287404209 has 9 divisors (see below), whose sum is σ = 415212889. Its totient is φ = 191568900.

The previous prime is 287404199. The next prime is 287404223. The reversal of 287404209 is 902404782.

The square root of 287404209 is 16953.

It is a perfect power (a square), and thus also a powerful number.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 287404209 - 2⁵ = 287404177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (287404259) 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 in 8 ways as a sum of consecutive naturals, for example, 48034 + ... + 53684.

Almost surely, 2^287404209 is an apocalyptic number.

287404209 is the 16953-rd square number.

287404209 is the 8477-th centered octagonal number.

It is an amenable number.

287404209 is a deficient number, since it is larger than the sum of its proper divisors (127808680).

287404209 is an frugal number, since it uses more digits than its factorization.

287404209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11308 (or 5654 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The cubic root of 287404209 is about 659.9297514764.

Multiplying 287404209 by its sum of digits (36), we get a square (10346551524 = 101718²).

It can be divided in two parts, 287 and 404209, that added together give a square (404496 = 636²).

The spelling of 287404209 in words is "two hundred eighty-seven million, four hundred four thousand, two hundred nine".