20340509 has 4 divisors (see below), whose sum is σ = 23246304. Its totient is φ = 17434716.

The previous prime is 20340497. The next prime is 20340521. The reversal of 20340509 is 90504302.

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 an interprime number because it is at equal distance from previous prime (20340497) and next prime (20340521).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20340509 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 (20340539) 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, 1452887 + ... + 1452900.

It is an arithmetic number, because the mean of its divisors is an integer number (5811576).

Almost surely, 2^20340509 is an apocalyptic number.

It is an amenable number.

20340509 is a deficient number, since it is larger than the sum of its proper divisors (2905795).

20340509 is an equidigital number, since it uses as much as digits as its factorization.

20340509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2905794.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 20340509 is about 4510.0453434528. The cubic root of 20340509 is about 272.9735737233.

The spelling of 20340509 in words is "twenty million, three hundred forty thousand, five hundred nine".