287881081 has 4 divisors (see below), whose sum is σ = 287968372. Its totient is φ = 287793792.

The previous prime is 287881067. The next prime is 287881117. The reversal of 287881081 is 180188782.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 180188782 = 2 ⋅90094391.

It can be written as a sum of positive squares in 2 ways, for example, as 110565225 + 177315856 = 10515^2 + 13316^2 .

It is a cyclic number.

It is not a de Polignac number, because 287881081 - 2⁷ = 287880953 is a prime.

It is a super-2 number, since 2×287881081² = 165751033595457122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (287881051) 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, 38496 + ... + 45361.

It is an arithmetic number, because the mean of its divisors is an integer number (71992093).

Almost surely, 2^287881081 is an apocalyptic number.

It is an amenable number.

287881081 is a deficient number, since it is larger than the sum of its proper divisors (87291).

287881081 is an equidigital number, since it uses as much as digits as its factorization.

287881081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87290.

The product of its (nonzero) digits is 57344, while the sum is 43.

The square root of 287881081 is about 16967.0587020850. The cubic root of 287881081 is about 660.2945433104.

The spelling of 287881081 in words is "two hundred eighty-seven million, eight hundred eighty-one thousand, eighty-one".