20145569 has 4 divisors (see below), whose sum is σ = 20234544. Its totient is φ = 20056596.

The previous prime is 20145557. The next prime is 20145571. The reversal of 20145569 is 96554102.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20145569 - 2⁸ = 20145313 is a prime.

It is a super-2 number, since 2×20145569² = 811687900667522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20145509) 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, 44147 + ... + 44600.

It is an arithmetic number, because the mean of its divisors is an integer number (5058636).

Almost surely, 2^20145569 is an apocalyptic number.

It is an amenable number.

20145569 is a deficient number, since it is larger than the sum of its proper divisors (88975).

20145569 is an equidigital number, since it uses as much as digits as its factorization.

20145569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88974.

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 20145569 is about 4488.3815568643. The cubic root of 20145569 is about 272.0987287575.

The spelling of 20145569 in words is "twenty million, one hundred forty-five thousand, five hundred sixty-nine".