20115569 has 4 divisors (see below), whose sum is σ = 20323044. Its totient is φ = 19908096.

The previous prime is 20115553. The next prime is 20115583. The reversal of 20115569 is 96551102.

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 13965169 + 6150400 = 3737^2 + 2480^2 .

It is a cyclic number.

It is not a de Polignac number, because 20115569 - 2⁴ = 20115553 is a prime.

It is a super-2 number, since 2×20115569² = 809272232387522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20111569) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 103592 + ... + 103785.

It is an arithmetic number, because the mean of its divisors is an integer number (5080761).

Almost surely, 2^20115569 is an apocalyptic number.

It is an amenable number.

20115569 is a deficient number, since it is larger than the sum of its proper divisors (207475).

20115569 is an equidigital number, since it uses as much as digits as its factorization.

20115569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207474.

The product of its (nonzero) digits is 2700, while the sum is 29.

The square root of 20115569 is about 4485.0383498918. The cubic root of 20115569 is about 271.9635953657.

The spelling of 20115569 in words is "twenty million, one hundred fifteen thousand, five hundred sixty-nine".