20061809 has 8 divisors (see below), whose sum is σ = 20656128. Its totient is φ = 19474560.

The previous prime is 20061799. The next prime is 20061827. The reversal of 20061809 is 90816002.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20061809 - 2⁴ = 20061793 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20061409) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4289 + ... + 7649.

It is an arithmetic number, because the mean of its divisors is an integer number (2582016).

Almost surely, 2^20061809 is an apocalyptic number.

It is an amenable number.

20061809 is a deficient number, since it is larger than the sum of its proper divisors (594319).

20061809 is a wasteful number, since it uses less digits than its factorization.

20061809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3535.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 20061809 is about 4479.0410804100. The cubic root of 20061809 is about 271.7210998274.

The spelling of 20061809 in words is "twenty million, sixty-one thousand, eight hundred nine".