1021287 has 4 divisors (see below), whose sum is σ = 1361720. Its totient is φ = 680856.

The previous prime is 1021283. The next prime is 1021289. The reversal of 1021287 is 7821201.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1021287 - 2² = 1021283 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 170212 + ... + 170217.

It is an arithmetic number, because the mean of its divisors is an integer number (340430).

2^1021287 is an apocalyptic number.

1021287 is a deficient number, since it is larger than the sum of its proper divisors (340433).

1021287 is an equidigital number, since it uses as much as digits as its factorization.

1021287 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340432.

The product of its (nonzero) digits is 224, while the sum is 21.

The square root of 1021287 is about 1010.5874529203. The cubic root of 1021287 is about 100.7045905288.

Adding to 1021287 its reverse (7821201), we get a palindrome (8842488).

The spelling of 1021287 in words is "one million, twenty-one thousand, two hundred eighty-seven".