1287798165 has 24 divisors (see below), whose sum is σ = 2248253280. Its totient is φ = 681881184.

The previous prime is 1287798143. The next prime is 1287798257. The reversal of 1287798165 is 5618977821.

It is not a de Polignac number, because 1287798165 - 2¹⁵ = 1287765397 is a prime.

It is a super-2 number, since 2×1287798165² = 3316848227554734450, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 96687 + ... + 109196.

It is an arithmetic number, because the mean of its divisors is an integer number (93677220).

Almost surely, 2^1287798165 is an apocalyptic number.

1287798165 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1287798165 is a deficient number, since it is larger than the sum of its proper divisors (960455115).

1287798165 is a wasteful number, since it uses less digits than its factorization.

1287798165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206033 (or 206030 counting only the distinct ones).

The product of its digits is 1693440, while the sum is 54.

The square root of 1287798165 is about 35885.9048234819. The cubic root of 1287798165 is about 1087.9675294542.

The spelling of 1287798165 in words is "one billion, two hundred eighty-seven million, seven hundred ninety-eight thousand, one hundred sixty-five".