1287801275018 has 4 divisors (see below), whose sum is σ = 1931701912530. Its totient is φ = 643900637508.

The previous prime is 1287801275011. The next prime is 1287801275029. The reversal of 1287801275018 is 8105721087821.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1282572105049 + 5229169969 = 1132507^2 + 72313^2 .

It is not an unprimeable number, because it can be changed into a prime (1287801275011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321950318753 + ... + 321950318756.

Almost surely, 2^{1287801275018} is an apocalyptic number.

1287801275018 is a deficient number, since it is larger than the sum of its proper divisors (643900637512).

1287801275018 is an equidigital number, since it uses as much as digits as its factorization.

1287801275018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 643900637511.

The product of its (nonzero) digits is 501760, while the sum is 50.

The spelling of 1287801275018 in words is "one trillion, two hundred eighty-seven billion, eight hundred one million, two hundred seventy-five thousand, eighteen".