1243 has 4 divisors (see below), whose sum is σ = 1368. Its totient is φ = 1120.

The previous prime is 1237. The next prime is 1249. The reversal of 1243 is 3421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3421 = 11 ⋅311.

It is an interprime number because it is at equal distance from previous prime (1237) and next prime (1249).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1243 is a prime.

It is a Duffinian number.

It is a plaindrome in base 8 and base 15.

It is a nialpdrome in base 6, base 11 and base 12.

It is not an unprimeable number, because it can be changed into a prime (1249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46 + ... + 67.

It is an arithmetic number, because the mean of its divisors is an integer number (342).

2¹²⁴³ is an apocalyptic number.

1243 is a deficient number, since it is larger than the sum of its proper divisors (125).

1243 is a wasteful number, since it uses less digits than its factorization.

1243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124.

The product of its digits is 24, while the sum is 10.

The square root of 1243 is about 35.2562051276. The cubic root of 1243 is about 10.7520277408.

Adding to 1243 its reverse (3421), we get a palindrome (4664).

It can be divided in two parts, 12 and 43, that added together give a palindrome (55).

The spelling of 1243 in words is "one thousand, two hundred forty-three", and thus it is an iban number.