20536403 has 4 divisors (see below), whose sum is σ = 20728440. Its totient is φ = 20344368.

The previous prime is 20536393. The next prime is 20536421. The reversal of 20536403 is 30463502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 30463502 = 2 ⋅15231751.

It is a cyclic number.

It is not a de Polignac number, because 20536403 - 2⁶ = 20536339 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20538403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 95858 + ... + 96071.

It is an arithmetic number, because the mean of its divisors is an integer number (5182110).

Almost surely, 2^20536403 is an apocalyptic number.

20536403 is a deficient number, since it is larger than the sum of its proper divisors (192037).

20536403 is a wasteful number, since it uses less digits than its factorization.

20536403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 192036.

The product of its (nonzero) digits is 2160, while the sum is 23.

The square root of 20536403 is about 4531.7108248431. The cubic root of 20536403 is about 273.8470873219.

Adding to 20536403 its reverse (30463502), we get a palindrome (50999905).

The spelling of 20536403 in words is "twenty million, five hundred thirty-six thousand, four hundred three".