20809735 has 8 divisors (see below), whose sum is σ = 25201440. Its totient is φ = 16494624.

The previous prime is 20809729. The next prime is 20809757. The reversal of 20809735 is 53790802.

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 20809735 - 2⁹ = 20809223 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20809735.

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, 18547 + ... + 19636.

It is an arithmetic number, because the mean of its divisors is an integer number (3150180).

Almost surely, 2^20809735 is an apocalyptic number.

20809735 is a deficient number, since it is larger than the sum of its proper divisors (4391705).

20809735 is a wasteful number, since it uses less digits than its factorization.

20809735 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38297.

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 20809735 is about 4561.7688455247. The cubic root of 20809735 is about 275.0566715160.

The spelling of 20809735 in words is "twenty million, eight hundred nine thousand, seven hundred thirty-five".