287220816 has 50 divisors (see below), whose sum is σ = 831304122. Its totient is φ = 95739840.

The previous prime is 287220811. The next prime is 287220823. The reversal of 287220816 is 618022782.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 249766416 + 37454400 = 15804^2 + 6120^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (287220811) 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 9 ways as a sum of consecutive naturals, for example, 109515 + ... + 112106.

Almost surely, 2^287220816 is an apocalyptic number.

It is an amenable number.

287220816 is an abundant number, since it is smaller than the sum of its proper divisors (544083306).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

287220816 is a wasteful number, since it uses less digits than its factorization.

287220816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221641 (or 221626 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 287220816 is about 16947.5902711860. The cubic root of 287220816 is about 659.7893542650.

The spelling of 287220816 in words is "two hundred eighty-seven million, two hundred twenty thousand, eight hundred sixteen".