1287738 has 20 divisors (see below), whose sum is σ = 2885850. Its totient is φ = 429192.

The previous prime is 1287731. The next prime is 1287739. The reversal of 1287738 is 8377821.

It can be written as a sum of positive squares in only one way, i.e., 1108809 + 178929 = 1053^2 + 423^2 .

It is not an unprimeable number, because it can be changed into a prime (1287731) by changing a digit.

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 9 ways as a sum of consecutive naturals, for example, 3813 + ... + 4136.

2^1287738 is an apocalyptic number.

1287738 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1287738 is an abundant number, since it is smaller than the sum of its proper divisors (1598112).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1287738 is an equidigital number, since it uses as much as digits as its factorization.

1287738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7963 (or 7954 counting only the distinct ones).

The product of its digits is 18816, while the sum is 36.

The square root of 1287738 is about 1134.7854422753. The cubic root of 1287738 is about 108.7950586171.

It can be divided in two parts, 1287 and 738, that added together give a square (2025 = 45²).

The spelling of 1287738 in words is "one million, two hundred eighty-seven thousand, seven hundred thirty-eight".