20111005 has 4 divisors (see below), whose sum is σ = 24133212. Its totient is φ = 16088800.

The previous prime is 20110997. The next prime is 20111011. The reversal of 20111005 is 50011102.

It is a happy number.

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 14830201 + 5280804 = 3851^2 + 2298^2 .

It is not a de Polignac number, because 20111005 - 2³ = 20110997 is a prime.

It is a super-2 number, since 2×20111005² = 808905044220050, 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 = 20110982 and 20111000.

It is a congruent 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, 2011096 + ... + 2011105.

It is an arithmetic number, because the mean of its divisors is an integer number (6033303).

Almost surely, 2^20111005 is an apocalyptic number.

It is an amenable number.

20111005 is a deficient number, since it is larger than the sum of its proper divisors (4022207).

20111005 is an equidigital number, since it uses as much as digits as its factorization.

20111005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4022206.

The product of its (nonzero) digits is 10, while the sum is 10.

The square root of 20111005 is about 4484.5295182438. The cubic root of 20111005 is about 271.9430252999.

Adding to 20111005 its reverse (50011102), we get a palindrome (70122107).

It can be divided in two parts, 2011 and 1005, that multiplied together give a triangular number (2021055 = T₂₀₁₀).

The spelling of 20111005 in words is "twenty million, one hundred eleven thousand, five".