1023 has 8 divisors (see below), whose sum is σ = 1536. Its totient is φ = 600.

The previous prime is 1021. The next prime is 1031. The reversal of 1023 is 3201.

1023 is nontrivially palindromic in base 2 and base 4.

It is a Cunningham number, because it is equal to 2¹⁰-1.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1023 - 2¹ = 1021 is a prime.

It is an Ulam number.

It is a D-number.

1023 is a lucky number.

1023 is a nontrivial repdigit in base 2 and base 4.

It is a plaindrome in base 2, base 4, base 8, base 9 and base 16.

It is a nialpdrome in base 2, base 4, base 11 and base 14.

It is a zygodrome in base 2 and base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021) by changing a digit.

Being equal to 4×4⁴-1, it is a generalized Woodall number.

It is a nontrivial repunit in base 2.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18 + ... + 48.

It is an arithmetic number, because the mean of its divisors is an integer number (192).

1023 is a deficient number, since it is larger than the sum of its proper divisors (513).

1023 is a wasteful number, since it uses less digits than its factorization.

1023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45.

The product of its (nonzero) digits is 6, while the sum is 6.

The square root of 1023 is about 31.9843711834. The cubic root of 1023 is about 10.0760862861.

Adding to 1023 its reverse (3201), we get a palindrome (4224).

It can be divided in two parts, 102 and 3, that added together give a triangular number (105 = T₁₄).

The spelling of 1023 in words is "one thousand, twenty-three", and thus it is an iban number.