20685585 has 32 divisors (see below), whose sum is σ = 35118720. Its totient is φ = 10368000.

The previous prime is 20685571. The next prime is 20685589. The reversal of 20685585 is 58558602.

It is not a de Polignac number, because 20685585 - 2⁴ = 20685569 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20685589) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 51385 + ... + 51785.

It is an arithmetic number, because the mean of its divisors is an integer number (1097460).

Almost surely, 2^20685585 is an apocalyptic number.

It is an amenable number.

20685585 is a deficient number, since it is larger than the sum of its proper divisors (14433135).

20685585 is a wasteful number, since it uses less digits than its factorization.

20685585 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 609.

The product of its (nonzero) digits is 96000, while the sum is 39.

The square root of 20685585 is about 4548.1408289542. The cubic root of 20685585 is about 274.5085879576.

The spelling of 20685585 in words is "twenty million, six hundred eighty-five thousand, five hundred eighty-five".