20542403 has 4 divisors (see below), whose sum is σ = 23477040. Its totient is φ = 17607768.

The previous prime is 20542399. The next prime is 20542447. The reversal of 20542403 is 30424502.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20542403 - 2² = 20542399 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20542453) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1467308 + ... + 1467321.

It is an arithmetic number, because the mean of its divisors is an integer number (5869260).

Almost surely, 2^20542403 is an apocalyptic number.

20542403 is a deficient number, since it is larger than the sum of its proper divisors (2934637).

20542403 is an equidigital number, since it uses as much as digits as its factorization.

20542403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2934636.

The product of its (nonzero) digits is 960, while the sum is 20.

The square root of 20542403 is about 4532.3727781373. The cubic root of 20542403 is about 273.8737541556.

Adding to 20542403 its reverse (30424502), we get a palindrome (50966905).

The spelling of 20542403 in words is "twenty million, five hundred forty-two thousand, four hundred three".