20010505 has 4 divisors (see below), whose sum is σ = 24012612. Its totient is φ = 16008400.

The previous prime is 20010491. The next prime is 20010517. The reversal of 20010505 is 50501002.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50501002 = 2 ⋅25250501.

It can be written as a sum of positive squares in 2 ways, for example, as 2134521 + 17875984 = 1461^2 + 4228^2 .

It is not a de Polignac number, because 20010505 - 2¹³ = 20002313 is a prime.

It is a Smith number, since the sum of its digits (13) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2001046 + ... + 2001055.

It is an arithmetic number, because the mean of its divisors is an integer number (6003153).

Almost surely, 2^20010505 is an apocalyptic number.

It is an amenable number.

20010505 is a deficient number, since it is larger than the sum of its proper divisors (4002107).

20010505 is an equidigital number, since it uses as much as digits as its factorization.

20010505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4002106.

The product of its (nonzero) digits is 50, while the sum is 13.

The square root of 20010505 is about 4473.3102955194. The cubic root of 20010505 is about 271.4892782695.

Adding to 20010505 its reverse (50501002), we get a palindrome (70511507).

The spelling of 20010505 in words is "twenty million, ten thousand, five hundred five".