20010865 has 12 divisors (see below), whose sum is σ = 27933876. Its totient is φ = 13721568.

The previous prime is 20010863. The next prime is 20010871. The reversal of 20010865 is 56801002.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 6964321 + 13046544 = 2639^2 + 3612^2 .

It is not a de Polignac number, because 20010865 - 2¹ = 20010863 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20010863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 40594 + ... + 41083.

It is an arithmetic number, because the mean of its divisors is an integer number (2327823).

Almost surely, 2^20010865 is an apocalyptic number.

It is an amenable number.

20010865 is a deficient number, since it is larger than the sum of its proper divisors (7923011).

20010865 is an equidigital number, since it uses as much as digits as its factorization.

20010865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81696 (or 81689 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 20010865 is about 4473.3505339957. The cubic root of 20010865 is about 271.4909063403.

Adding to 20010865 its reverse (56801002), we get a palindrome (76811867).

The spelling of 20010865 in words is "twenty million, ten thousand, eight hundred sixty-five".