1287638 has 16 divisors (see below), whose sum is σ = 2130624. Its totient is φ = 578760.

The previous prime is 1287623. The next prime is 1287661. The reversal of 1287638 is 8367821.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1287598 and 1287607.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2081 + ... + 2627.

It is an arithmetic number, because the mean of its divisors is an integer number (133164).

2^1287638 is an apocalyptic number.

1287638 is a deficient number, since it is larger than the sum of its proper divisors (842986).

1287638 is a wasteful number, since it uses less digits than its factorization.

1287638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 667.

The product of its digits is 16128, while the sum is 35.

The square root of 1287638 is about 1134.7413802272. The cubic root of 1287638 is about 108.7922423643.

The spelling of 1287638 in words is "one million, two hundred eighty-seven thousand, six hundred thirty-eight".