20403845 has 48 divisors (see below), whose sum is σ = 31814208. Its totient is φ = 12418560.

The previous prime is 20403841. The next prime is 20403847. The reversal of 20403845 is 54830402.

It is not a de Polignac number, because 20403845 - 2² = 20403841 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20403841) 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 47 ways as a sum of consecutive naturals, for example, 180509 + ... + 180621.

It is an arithmetic number, because the mean of its divisors is an integer number (662796).

Almost surely, 2^20403845 is an apocalyptic number.

It is an amenable number.

20403845 is a deficient number, since it is larger than the sum of its proper divisors (11410363).

20403845 is a wasteful number, since it uses less digits than its factorization.

20403845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210 (or 203 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 26.

The square root of 20403845 is about 4517.0615448541. The cubic root of 20403845 is about 273.2566072901.

It can be divided in two parts, 2040 and 3845, that added together give a palindrome (5885).

The spelling of 20403845 in words is "twenty million, four hundred three thousand, eight hundred forty-five".