20135865 has 16 divisors (see below), whose sum is σ = 32538816. Its totient is φ = 10632000.

The previous prime is 20135827. The next prime is 20135867. The reversal of 20135865 is 56853102.

It is not a de Polignac number, because 20135865 - 2⁷ = 20135737 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20135867) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5131 + ... + 8160.

It is an arithmetic number, because the mean of its divisors is an integer number (2033676).

Almost surely, 2^20135865 is an apocalyptic number.

It is an amenable number.

20135865 is a deficient number, since it is larger than the sum of its proper divisors (12402951).

20135865 is a wasteful number, since it uses less digits than its factorization.

20135865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13400.

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 20135865 is about 4487.3004133889. The cubic root of 20135865 is about 272.0550322977.

Adding to 20135865 its reverse (56853102), we get a palindrome (76988967).

The spelling of 20135865 in words is "twenty million, one hundred thirty-five thousand, eight hundred sixty-five".