20508686 has 16 divisors (see below), whose sum is σ = 35019648. Its totient is φ = 8916600.

The previous prime is 20508661. The next prime is 20508703. The reversal of 20508686 is 68680502.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19760 + ... + 20771.

It is an arithmetic number, because the mean of its divisors is an integer number (2188728).

Almost surely, 2^20508686 is an apocalyptic number.

20508686 is a deficient number, since it is larger than the sum of its proper divisors (14510962).

20508686 is a wasteful number, since it uses less digits than its factorization.

20508686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40567.

The product of its (nonzero) digits is 23040, while the sum is 35.

The square root of 20508686 is about 4528.6516757198. The cubic root of 20508686 is about 273.7238324202.

The spelling of 20508686 in words is "twenty million, five hundred eight thousand, six hundred eighty-six".