20479569 has 16 divisors (see below), whose sum is σ = 29963520. Its totient is φ = 12338960.

The previous prime is 20479553. The next prime is 20479579. The reversal of 20479569 is 96597402.

It is a cyclic number.

It is not a de Polignac number, because 20479569 - 2⁴ = 20479553 is a prime.

It is a super-2 number, since 2×20479569² = 838825492851522, which contains 22 as substring.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 20479569.

It is not an unprimeable number, because it can be changed into a prime (20479519) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 4174 + ... + 7640.

It is an arithmetic number, because the mean of its divisors is an integer number (1872720).

Almost surely, 2^20479569 is an apocalyptic number.

It is an amenable number.

20479569 is a deficient number, since it is larger than the sum of its proper divisors (9483951).

20479569 is a wasteful number, since it uses less digits than its factorization.

20479569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3660.

The product of its (nonzero) digits is 136080, while the sum is 42.

The square root of 20479569 is about 4525.4357801211. The cubic root of 20479569 is about 273.5942321849.

The spelling of 20479569 in words is "twenty million, four hundred seventy-nine thousand, five hundred sixty-nine".