20540409 has 4 divisors (see below), whose sum is σ = 27387216. Its totient is φ = 13693604.

The previous prime is 20540393. The next prime is 20540413. The reversal of 20540409 is 90404502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20540409 - 2⁴ = 20540393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20540419) 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, 3423399 + ... + 3423404.

It is an arithmetic number, because the mean of its divisors is an integer number (6846804).

Almost surely, 2^20540409 is an apocalyptic number.

It is an amenable number.

20540409 is a deficient number, since it is larger than the sum of its proper divisors (6846807).

20540409 is an equidigital number, since it uses as much as digits as its factorization.

20540409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6846806.

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 20540409 is about 4532.1527997189. The cubic root of 20540409 is about 273.8648924540.

The spelling of 20540409 in words is "twenty million, five hundred forty thousand, four hundred nine".