20689085 has 8 divisors (see below), whose sum is σ = 26287416. Its totient is φ = 15577600.

The previous prime is 20689061. The next prime is 20689087. The reversal of 20689085 is 58098602.

It can be written as a sum of positive squares in 4 ways, for example, as 3829849 + 16859236 = 1957^2 + 4106^2 .

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

It is not a de Polignac number, because 20689085 - 2¹⁸ = 20426941 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20689087) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 121616 + ... + 121785.

It is an arithmetic number, because the mean of its divisors is an integer number (3285927).

Almost surely, 2^20689085 is an apocalyptic number.

It is an amenable number.

20689085 is a deficient number, since it is larger than the sum of its proper divisors (5598331).

20689085 is a wasteful number, since it uses less digits than its factorization.

20689085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243423.

The product of its (nonzero) digits is 34560, while the sum is 38.

The square root of 20689085 is about 4548.5255852859. The cubic root of 20689085 is about 274.5240693645.

The spelling of 20689085 in words is "twenty million, six hundred eighty-nine thousand, eighty-five".