20907085 has 4 divisors (see below), whose sum is σ = 25088508. Its totient is φ = 16725664.

The previous prime is 20907077. The next prime is 20907091. The reversal of 20907085 is 58070902.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16232841 + 4674244 = 4029^2 + 2162^2 .

It is a cyclic number.

It is not a de Polignac number, because 20907085 - 2³ = 20907077 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2090704 + ... + 2090713.

It is an arithmetic number, because the mean of its divisors is an integer number (6272127).

Almost surely, 2^20907085 is an apocalyptic number.

It is an amenable number.

20907085 is a deficient number, since it is larger than the sum of its proper divisors (4181423).

20907085 is an equidigital number, since it uses as much as digits as its factorization.

20907085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4181422.

The product of its (nonzero) digits is 5040, while the sum is 31.

The square root of 20907085 is about 4572.4265986454. The cubic root of 20907085 is about 275.4849185258.

Adding to 20907085 its reverse (58070902), we get a palindrome (78977987).

The spelling of 20907085 in words is "twenty million, nine hundred seven thousand, eighty-five".