20403423 has 6 divisors (see below), whose sum is σ = 29471624. Its totient is φ = 13602276.

The previous prime is 20403419. The next prime is 20403431. The reversal of 20403423 is 32430402.

It is not a de Polignac number, because 20403423 - 2² = 20403419 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20403396 and 20403405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20403413) 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, 1133515 + ... + 1133532.

Almost surely, 2^20403423 is an apocalyptic number.

20403423 is a deficient number, since it is larger than the sum of its proper divisors (9068201).

20403423 is a wasteful number, since it uses less digits than its factorization.

20403423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2267053 (or 2267050 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 18.

The square root of 20403423 is about 4517.0148328293. The cubic root of 20403423 is about 273.2547234118.

Adding to 20403423 its reverse (32430402), we get a palindrome (52833825).

The spelling of 20403423 in words is "twenty million, four hundred three thousand, four hundred twenty-three".