20857805 has 8 divisors (see below), whose sum is σ = 25062912. Its totient is φ = 16663888.

The previous prime is 20857783. The next prime is 20857829. The reversal of 20857805 is 50875802.

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 20857805 - 2¹⁴ = 20841421 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, 2084 + ... + 6786.

It is an arithmetic number, because the mean of its divisors is an integer number (3132864).

Almost surely, 2^20857805 is an apocalyptic number.

It is an amenable number.

20857805 is a deficient number, since it is larger than the sum of its proper divisors (4205107).

20857805 is an equidigital number, since it uses as much as digits as its factorization.

20857805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5595.

The product of its (nonzero) digits is 22400, while the sum is 35.

The square root of 20857805 is about 4567.0345958839. The cubic root of 20857805 is about 275.2683001348.

The spelling of 20857805 in words is "twenty million, eight hundred fifty-seven thousand, eight hundred five".