20520169 has 4 divisors (see below), whose sum is σ = 20907396. Its totient is φ = 20132944.

The previous prime is 20520167. The next prime is 20520179. The reversal of 20520169 is 96102502.

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 18662400 + 1857769 = 4320^2 + 1363^2 .

It is a cyclic number.

It is not a de Polignac number, because 20520169 - 2¹ = 20520167 is a prime.

It is a super-2 number, since 2×20520169² = 842154671577122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20520161) 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 3 ways as a sum of consecutive naturals, for example, 193534 + ... + 193639.

It is an arithmetic number, because the mean of its divisors is an integer number (5226849).

Almost surely, 2^20520169 is an apocalyptic number.

It is an amenable number.

20520169 is a deficient number, since it is larger than the sum of its proper divisors (387227).

20520169 is an equidigital number, since it uses as much as digits as its factorization.

20520169 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 387226.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 20520169 is about 4529.9193149547. The cubic root of 20520169 is about 273.7749097104.

The spelling of 20520169 in words is "twenty million, five hundred twenty thousand, one hundred sixty-nine".