1287905 has 8 divisors (see below), whose sum is σ = 1555200. Its totient is φ = 1023856.

The previous prime is 1287899. The next prime is 1287917. The reversal of 1287905 is 5097821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1287905 - 2⁶ = 1287841 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 176 + ... + 1614.

It is an arithmetic number, because the mean of its divisors is an integer number (194400).

2^1287905 is an apocalyptic number.

It is an amenable number.

1287905 is a deficient number, since it is larger than the sum of its proper divisors (267295).

1287905 is a wasteful number, since it uses less digits than its factorization.

1287905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1623.

The product of its (nonzero) digits is 5040, while the sum is 32.

The square root of 1287905 is about 1134.8590220816. The cubic root of 1287905 is about 108.7997614344.

The spelling of 1287905 in words is "one million, two hundred eighty-seven thousand, nine hundred five".