20205019 has 4 divisors (see below), whose sum is σ = 20239240. Its totient is φ = 20170800.

The previous prime is 20205001. The next prime is 20205023. The reversal of 20205019 is 91050202.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20205019 - 2¹⁷ = 20073947 is a prime.

It is a super-2 number, since 2×20205019² = 816485585580722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20204987 and 20205005.

It is not an unprimeable number, because it can be changed into a prime (20202019) 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, 16209 + ... + 17410.

It is an arithmetic number, because the mean of its divisors is an integer number (5059810).

Almost surely, 2^20205019 is an apocalyptic number.

20205019 is a deficient number, since it is larger than the sum of its proper divisors (34221).

20205019 is an equidigital number, since it uses as much as digits as its factorization.

20205019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34220.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 20205019 is about 4494.9993325917. Note that the first 3 decimals coincide. The cubic root of 20205019 is about 272.3661222687.

The spelling of 20205019 in words is "twenty million, two hundred five thousand, nineteen".