20708857 has 8 divisors (see below), whose sum is σ = 22385160. Its totient is φ = 19044480.

The previous prime is 20708851. The next prime is 20708867. The reversal of 20708857 is 75880702.

It can be written as a sum of positive squares in 4 ways, for example, as 467856 + 20241001 = 684^2 + 4499^2 .

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

It is not a de Polignac number, because 20708857 - 2⁷ = 20708729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20708851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 819 + ... + 6487.

It is an arithmetic number, because the mean of its divisors is an integer number (2798145).

Almost surely, 2^20708857 is an apocalyptic number.

It is an amenable number.

20708857 is a deficient number, since it is larger than the sum of its proper divisors (1676303).

20708857 is a wasteful number, since it uses less digits than its factorization.

20708857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5963.

The product of its (nonzero) digits is 31360, while the sum is 37.

The square root of 20708857 is about 4550.6985178102. The cubic root of 20708857 is about 274.6114932682.

The spelling of 20708857 in words is "twenty million, seven hundred eight thousand, eight hundred fifty-seven".