20705685 has 96 divisors (see below), whose sum is σ = 45505152. Its totient is φ = 7902720.

The previous prime is 20705683. The next prime is 20705701. The reversal of 20705685 is 58650702.

It is a happy number.

It is not a de Polignac number, because 20705685 - 2¹ = 20705683 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20705683) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 105007 + ... + 105203.

It is an arithmetic number, because the mean of its divisors is an integer number (474012).

Almost surely, 2^20705685 is an apocalyptic number.

It is an amenable number.

20705685 is an abundant number, since it is smaller than the sum of its proper divisors (24799467).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20705685 is a wasteful number, since it uses less digits than its factorization.

20705685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243 (or 236 counting only the distinct ones).

The product of its (nonzero) digits is 16800, while the sum is 33.

The square root of 20705685 is about 4550.3499865395. The cubic root of 20705685 is about 274.5974716970.

The spelling of 20705685 in words is "twenty million, seven hundred five thousand, six hundred eighty-five".