20859805 has 8 divisors (see below), whose sum is σ = 25192152. Its totient is φ = 16580928.

The previous prime is 20859737. The next prime is 20859841. The reversal of 20859805 is 50895802.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 6563844 + 14295961 = 2562^2 + 3781^2 .

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 20859805 - 2¹⁷ = 20728733 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12502 + ... + 14071.

It is an arithmetic number, because the mean of its divisors is an integer number (3149019).

Almost surely, 2^20859805 is an apocalyptic number.

It is an amenable number.

20859805 is a deficient number, since it is larger than the sum of its proper divisors (4332347).

20859805 is a wasteful number, since it uses less digits than its factorization.

20859805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26735.

The product of its (nonzero) digits is 28800, while the sum is 37.

The square root of 20859805 is about 4567.2535510961. The cubic root of 20859805 is about 275.2770981045.

The spelling of 20859805 in words is "twenty million, eight hundred fifty-nine thousand, eight hundred five".