20265865 has 4 divisors (see below), whose sum is σ = 24319044. Its totient is φ = 16212688.

The previous prime is 20265863. The next prime is 20265871. The reversal of 20265865 is 56856202.

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 2524921 + 17740944 = 1589^2 + 4212^2 .

It is a cyclic number.

It is not a de Polignac number, because 20265865 - 2¹ = 20265863 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20265865.

It is not an unprimeable number, because it can be changed into a prime (20265863) 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 3 ways as a sum of consecutive naturals, for example, 2026582 + ... + 2026591.

It is an arithmetic number, because the mean of its divisors is an integer number (6079761).

Almost surely, 2^20265865 is an apocalyptic number.

It is an amenable number.

20265865 is a deficient number, since it is larger than the sum of its proper divisors (4053179).

20265865 is an equidigital number, since it uses as much as digits as its factorization.

20265865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4053178.

The product of its (nonzero) digits is 28800, while the sum is 34.

The square root of 20265865 is about 4501.7624326479. The cubic root of 20265865 is about 272.6392521170.

The spelling of 20265865 in words is "twenty million, two hundred sixty-five thousand, eight hundred sixty-five".