20056809 has 4 divisors (see below), whose sum is σ = 26742416. Its totient is φ = 13371204.

The previous prime is 20056807. The next prime is 20056811. The reversal of 20056809 is 90865002.

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 (20056807) and next prime (20056811).

It is not a de Polignac number, because 20056809 - 2¹ = 20056807 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20056807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3342799 + ... + 3342804.

It is an arithmetic number, because the mean of its divisors is an integer number (6685604).

Almost surely, 2^20056809 is an apocalyptic number.

It is an amenable number.

20056809 is a deficient number, since it is larger than the sum of its proper divisors (6685607).

20056809 is an equidigital number, since it uses as much as digits as its factorization.

20056809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6685606.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 20056809 is about 4478.4828904440. The cubic root of 20056809 is about 271.6985242896.

The spelling of 20056809 in words is "twenty million, fifty-six thousand, eight hundred nine".