20138305 has 16 divisors (see below), whose sum is σ = 26495424. Its totient is φ = 14572480.

The previous prime is 20138303. The next prime is 20138311. The reversal of 20138305 is 50383102.

It is not a de Polignac number, because 20138305 - 2¹ = 20138303 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20138303) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11679 + ... + 13291.

It is an arithmetic number, because the mean of its divisors is an integer number (1655964).

Almost surely, 2^20138305 is an apocalyptic number.

It is an amenable number.

20138305 is a deficient number, since it is larger than the sum of its proper divisors (6357119).

20138305 is a wasteful number, since it uses less digits than its factorization.

20138305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1856.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 20138305 is about 4487.5722835404. The cubic root of 20138305 is about 272.0660207747.

The spelling of 20138305 in words is "twenty million, one hundred thirty-eight thousand, three hundred five".