1287647 has 8 divisors (see below), whose sum is σ = 1349760. Its totient is φ = 1226880.

The previous prime is 1287623. The next prime is 1287661. The reversal of 1287647 is 7467821.

It is a happy number.

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 1287647 - 2¹⁸ = 1025503 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1287607) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1979 + ... + 2547.

It is an arithmetic number, because the mean of its divisors is an integer number (168720).

2^1287647 is an apocalyptic number.

1287647 is a deficient number, since it is larger than the sum of its proper divisors (62113).

1287647 is an equidigital number, since it uses as much as digits as its factorization.

1287647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 673.

The product of its digits is 18816, while the sum is 35.

The square root of 1287647 is about 1134.7453458816. The cubic root of 1287647 is about 108.7924958330.

The spelling of 1287647 in words is "one million, two hundred eighty-seven thousand, six hundred forty-seven".