It is a semiprime because it is the product of two primes.
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-1121647 is a prime.
It is a Duffinian number.
It is a congruent number.
21121647 is an apocalyptic number.
1121647 is an equidigital number, since it uses as much as digits as its factorization.
1121647 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 16808.
The square root of 1121647 is about 1059.0783729262. The cubic root of 1121647 is about 103.9007620917.
Adding to 1121647 its reverse (7461211), we get a palindrome (8582858).
The spelling of 1121647 in words is "one million, one hundred twenty-one thousand, six hundred forty-seven".