20412565 has 4 divisors (see below), whose sum is σ = 24495084. Its totient is φ = 16330048.

The previous prime is 20412559. The next prime is 20412599. The reversal of 20412565 is 56521402.

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 5116644 + 15295921 = 2262^2 + 3911^2 .

It is a cyclic number.

It is not a de Polignac number, because 20412565 - 2¹¹ = 20410517 is a prime.

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, 2041252 + ... + 2041261.

It is an arithmetic number, because the mean of its divisors is an integer number (6123771).

Almost surely, 2^20412565 is an apocalyptic number.

It is an amenable number.

20412565 is a deficient number, since it is larger than the sum of its proper divisors (4082519).

20412565 is an equidigital number, since it uses as much as digits as its factorization.

20412565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4082518.

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 20412565 is about 4518.0266710147. The cubic root of 20412565 is about 273.2955290105.

Adding to 20412565 its reverse (56521402), we get a palindrome (76933967).

It can be divided in two parts, 204 and 12565, that added together give a square (12769 = 113²).

The spelling of 20412565 in words is "twenty million, four hundred twelve thousand, five hundred sixty-five".