20102565 has 16 divisors (see below), whose sum is σ = 36759168. Its totient is φ = 9189696.

The previous prime is 20102527. The next prime is 20102567. The reversal of 20102565 is 56520102.

It is not a de Polignac number, because 20102565 - 2⁸ = 20102309 is a prime.

It is a super-2 number, since 2×20102565² = 808226239158450, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20102567) 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, 95622 + ... + 95831.

It is an arithmetic number, because the mean of its divisors is an integer number (2297448).

Almost surely, 2^20102565 is an apocalyptic number.

It is an amenable number.

20102565 is a deficient number, since it is larger than the sum of its proper divisors (16656603).

20102565 is a wasteful number, since it uses less digits than its factorization.

20102565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191468.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 20102565 is about 4483.5884066225. The cubic root of 20102565 is about 271.9049778016.

Adding to 20102565 its reverse (56520102), we get a palindrome (76622667).

The spelling of 20102565 in words is "twenty million, one hundred two thousand, five hundred sixty-five".