1287065803 has 4 divisors (see below), whose sum is σ = 1287144648. Its totient is φ = 1286986960.

The previous prime is 1287065789. The next prime is 1287065807. The reversal of 1287065803 is 3085607821.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 3085607821 = 157 ⋅19653553.

It is a cyclic number.

It is not a de Polignac number, because 1287065803 - 2²⁹ = 750194891 is a prime.

It is a super-4 number, since 4×1287065803⁴ (a number of 38 digits) contains 4444 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1287065807) 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, 4801 + ... + 50962.

It is an arithmetic number, because the mean of its divisors is an integer number (321786162).

Almost surely, 2^1287065803 is an apocalyptic number.

1287065803 is a deficient number, since it is larger than the sum of its proper divisors (78845).

1287065803 is an equidigital number, since it uses as much as digits as its factorization.

1287065803 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78844.

The product of its (nonzero) digits is 80640, while the sum is 40.

The square root of 1287065803 is about 35875.6993381314. The cubic root of 1287065803 is about 1087.7612504509.

The spelling of 1287065803 in words is "one billion, two hundred eighty-seven million, sixty-five thousand, eight hundred three".