1281205125 has 24 divisors (see below), whose sum is σ = 2309587800. Its totient is φ = 683308800.

The previous prime is 1281205111. The next prime is 1281205139. The reversal of 1281205125 is 5215021821.

It is a happy number.

1281205125 is a `hidden beast` number, since 1 + 28 + 120 + 512 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (1281205111) and next prime (1281205139).

It can be written as a sum of positive squares in 4 ways, for example, as 17189316 + 1264015809 = 4146^2 + 35553^2 .

It is not a de Polignac number, because 1281205125 - 2¹⁰ = 1281204101 is a prime.

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, 568300 + ... + 570549.

It is an arithmetic number, because the mean of its divisors is an integer number (96232825).

Almost surely, 2^1281205125 is an apocalyptic number.

1281205125 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1281205125 is a deficient number, since it is larger than the sum of its proper divisors (1028382675).

1281205125 is a wasteful number, since it uses less digits than its factorization.

1281205125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1138870 (or 1138857 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 27.

The square root of 1281205125 is about 35793.9258115117. The cubic root of 1281205125 is about 1086.1076910595.

Adding to 1281205125 its reverse (5215021821), we get a palindrome (6496226946).

The spelling of 1281205125 in words is "one billion, two hundred eighty-one million, two hundred five thousand, one hundred twenty-five".