1321647 has 4 divisors (see below), whose sum is σ = 1762200. Its totient is φ = 881096.

The previous prime is 1321637. The next prime is 1321651. The reversal of 1321647 is 7461231.

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

It is a cyclic number.

It is not a de Polignac number, because 1321647 - 2⁸ = 1321391 is a prime.

It is a D-number.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321627) 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 3 ways as a sum of consecutive naturals, for example, 220272 + ... + 220277.

It is an arithmetic number, because the mean of its divisors is an integer number (440550).

2^1321647 is an apocalyptic number.

1321647 is a deficient number, since it is larger than the sum of its proper divisors (440553).

1321647 is an equidigital number, since it uses as much as digits as its factorization.

1321647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440552.

The product of its digits is 1008, while the sum is 24.

The square root of 1321647 is about 1149.6290706136. The cubic root of 1321647 is about 109.7417357047.

Adding to 1321647 its reverse (7461231), we get a palindrome (8782878).

The spelling of 1321647 in words is "one million, three hundred twenty-one thousand, six hundred forty-seven".