1287858 has 64 divisors (see below), whose sum is σ = 3225600. Its totient is φ = 336960.

The previous prime is 1287857. The next prime is 1287883. The reversal of 1287858 is 8587821.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1287857) 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 31 ways as a sum of consecutive naturals, for example, 16263 + ... + 16341.

It is an arithmetic number, because the mean of its divisors is an integer number (50400).

2^1287858 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1287858, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1612800).

1287858 is an abundant number, since it is smaller than the sum of its proper divisors (1937742).

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

1287858 is a wasteful number, since it uses less digits than its factorization.

1287858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127.

The product of its digits is 35840, while the sum is 39.

The square root of 1287858 is about 1134.8383144748. The cubic root of 1287858 is about 108.7984379281.

It can be divided in two parts, 1287 and 858, that added together give a triangular number (2145 = T₆₅).

The spelling of 1287858 in words is "one million, two hundred eighty-seven thousand, eight hundred fifty-eight".