1221743 has 4 divisors (see below), whose sum is σ = 1225440. Its totient is φ = 1218048.

The previous prime is 1221707. The next prime is 1221749. The reversal of 1221743 is 3471221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3471221 = 13 ⋅267017.

It is a cyclic number.

It is not a de Polignac number, because 1221743 - 2¹² = 1217647 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221749) 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, 1298 + ... + 2031.

It is an arithmetic number, because the mean of its divisors is an integer number (306360).

2^1221743 is an apocalyptic number.

1221743 is a deficient number, since it is larger than the sum of its proper divisors (3697).

1221743 is an equidigital number, since it uses as much as digits as its factorization.

1221743 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3696.

The product of its digits is 336, while the sum is 20.

The square root of 1221743 is about 1105.3248391310. The cubic root of 1221743 is about 106.9038353392.

Adding to 1221743 its reverse (3471221), we get a palindrome (4692964).

The spelling of 1221743 in words is "one million, two hundred twenty-one thousand, seven hundred forty-three".