1287129 has 4 divisors (see below), whose sum is σ = 1716176. Its totient is φ = 858084.

The previous prime is 1287109. The next prime is 1287131. The reversal of 1287129 is 9217821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9217821 = 3 ⋅3072607.

It is not a de Polignac number, because 1287129 - 2⁹ = 1286617 is a prime.

It is a D-number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1287096 and 1287105.

It is not an unprimeable number, because it can be changed into a prime (1287109) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 214519 + ... + 214524.

It is an arithmetic number, because the mean of its divisors is an integer number (429044).

2^1287129 is an apocalyptic number.

It is an amenable number.

1287129 is a deficient number, since it is larger than the sum of its proper divisors (429047).

1287129 is an equidigital number, since it uses as much as digits as its factorization.

1287129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 429046.

The product of its digits is 2016, while the sum is 30.

The square root of 1287129 is about 1134.5170778794. The cubic root of 1287129 is about 108.7779053768. Note that the first 3 decimals are identical.

The spelling of 1287129 in words is "one million, two hundred eighty-seven thousand, one hundred twenty-nine".