40023 has 6 divisors (see below), whose sum is σ = 57824. Its totient is φ = 26676.

The previous prime is 40013. The next prime is 40031. The reversal of 40023 is 32004.

It is not a de Polignac number, because 40023 - 2⁹ = 39511 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 4447 = 40023 / (4 + 0 + 0 + 2 + 3).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 39987 and 40014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40013) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2215 + ... + 2232.

2⁴⁰⁰²³ is an apocalyptic number.

40023 is a deficient number, since it is larger than the sum of its proper divisors (17801).

40023 is a wasteful number, since it uses less digits than its factorization.

40023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4453 (or 4450 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 9.

The square root of 40023 is about 200.0574917368. The cubic root of 40023 is about 34.2060725854.

Adding to 40023 its reverse (32004), we get a palindrome (72027).

It can be divided in two parts, 4002 and 3, that added together give a triangular number (4005 = T₈₉).

The spelling of 40023 in words is "forty thousand, twenty-three", and thus it is an iban number.