1287663 has 16 divisors (see below), whose sum is σ = 1870176. Its totient is φ = 783360.

The previous prime is 1287661. The next prime is 1287683. The reversal of 1287663 is 3667821.

It is not a de Polignac number, because 1287663 - 2¹ = 1287661 is a prime.

1287663 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1287661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5223 + ... + 5463.

It is an arithmetic number, because the mean of its divisors is an integer number (116886).

2^1287663 is an apocalyptic number.

1287663 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1287663 is a deficient number, since it is larger than the sum of its proper divisors (582513).

1287663 is a wasteful number, since it uses less digits than its factorization.

1287663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 394.

The product of its digits is 12096, while the sum is 33.

The square root of 1287663 is about 1134.7523958997. The cubic root of 1287663 is about 108.7929464412.

The spelling of 1287663 in words is "one million, two hundred eighty-seven thousand, six hundred sixty-three".