1281157173 has 12 divisors (see below), whose sum is σ = 1851109728. Its totient is φ = 853851240.

The previous prime is 1281157151. The next prime is 1281157187. The reversal of 1281157173 is 3717511821.

1281157173 is a `hidden beast` number, since 1 + 2 + 8 + 11 + 571 + 73 = 666.

It is not a de Polignac number, because 1281157173 - 2⁹ = 1281156661 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1281157193) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13936 + ... + 52502.

It is an arithmetic number, because the mean of its divisors is an integer number (154259144).

Almost surely, 2^1281157173 is an apocalyptic number.

It is an amenable number.

1281157173 is a deficient number, since it is larger than the sum of its proper divisors (569952555).

1281157173 is a wasteful number, since it uses less digits than its factorization.

1281157173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42264 (or 42261 counting only the distinct ones).

The product of its digits is 11760, while the sum is 36.

The square root of 1281157173 is about 35793.2559709228. The cubic root of 1281157173 is about 1086.0941408781.

Adding to 1281157173 its reverse (3717511821), we get a palindrome (4998668994).

The spelling of 1281157173 in words is "one billion, two hundred eighty-one million, one hundred fifty-seven thousand, one hundred seventy-three".