20069809 has 4 divisors (see below), whose sum is σ = 21250404. Its totient is φ = 18889216.

The previous prime is 20069807. The next prime is 20069813. The reversal of 20069809 is 90896002.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 17247409 + 2822400 = 4153^2 + 1680^2 .

It is a cyclic number.

It is not a de Polignac number, because 20069809 - 2¹ = 20069807 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20069807) 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 3 ways as a sum of consecutive naturals, for example, 590272 + ... + 590305.

It is an arithmetic number, because the mean of its divisors is an integer number (5312601).

Almost surely, 2^20069809 is an apocalyptic number.

It is an amenable number.

20069809 is a deficient number, since it is larger than the sum of its proper divisors (1180595).

20069809 is a wasteful number, since it uses less digits than its factorization.

20069809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1180594.

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 20069809 is about 4479.9340396930. The cubic root of 20069809 is about 271.7572128871.

The spelling of 20069809 in words is "twenty million, sixty-nine thousand, eight hundred nine".