20015565 has 8 divisors (see below), whose sum is σ = 32024928. Its totient is φ = 10674960.

The previous prime is 20015551. The next prime is 20015591. The reversal of 20015565 is 56551002.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20015565 - 2⁹ = 20015053 is a prime.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 667171 + ... + 667200.

It is an arithmetic number, because the mean of its divisors is an integer number (4003116).

Almost surely, 2^20015565 is an apocalyptic number.

It is an amenable number.

20015565 is a deficient number, since it is larger than the sum of its proper divisors (12009363).

20015565 is a wasteful number, since it uses less digits than its factorization.

20015565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1334379.

The product of its (nonzero) digits is 1500, while the sum is 24.

The square root of 20015565 is about 4473.8758364532. The cubic root of 20015565 is about 271.5121599172.

Adding to 20015565 its reverse (56551002), we get a palindrome (76566567).

The spelling of 20015565 in words is "twenty million, fifteen thousand, five hundred sixty-five".