1287378025 has 6 divisors (see below), whose sum is σ = 1596348782. Its totient is φ = 1029902400.

The previous prime is 1287378007. The next prime is 1287378047. The reversal of 1287378025 is 5208737821.

It can be written as a sum of positive squares in 3 ways, for example, as 393308224 + 894069801 = 19832^2 + 29901^2 .

It is not a de Polignac number, because 1287378025 - 2²¹ = 1285280873 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 25747536 + ... + 25747585.

Almost surely, 2^1287378025 is an apocalyptic number.

It is an amenable number.

1287378025 is a deficient number, since it is larger than the sum of its proper divisors (308970757).

1287378025 is an equidigital number, since it uses as much as digits as its factorization.

1287378025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51495131 (or 51495126 counting only the distinct ones).

The product of its (nonzero) digits is 188160, while the sum is 43.

The square root of 1287378025 is about 35880.0505155720. The cubic root of 1287378025 is about 1087.8492012854.

The spelling of 1287378025 in words is "one billion, two hundred eighty-seven million, three hundred seventy-eight thousand, twenty-five".