1287345917778 has 32 divisors (see below), whose sum is σ = 2613922660800. Its totient is φ = 422594678016.

The previous prime is 1287345917777. The next prime is 1287345917821. The reversal of 1287345917778 is 8777195437821.

It is a super-2 number, since 2×1287345917778² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1287345917773) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1941363 + ... + 2518646.

It is an arithmetic number, because the mean of its divisors is an integer number (81685083150).

Almost surely, 2^{1287345917778} is an apocalyptic number.

1287345917778 is an abundant number, since it is smaller than the sum of its proper divisors (1326576743022).

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

1287345917778 is a wasteful number, since it uses less digits than its factorization.

1287345917778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4460746.

The product of its digits is 165957120, while the sum is 69.

The spelling of 1287345917778 in words is "one trillion, two hundred eighty-seven billion, three hundred forty-five million, nine hundred seventeen thousand, seven hundred seventy-eight".