2021100605 has 4 divisors (see below), whose sum is σ = 2425320732. Its totient is φ = 1616880480.

The previous prime is 2021100593. The next prime is 2021100611. The reversal of 2021100605 is 5060011202.

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 1391140804 + 629959801 = 37298^2 + 25099^2 .

It is not a de Polignac number, because 2021100605 - 2⁴ = 2021100589 is a prime.

It is a Duffinian number.

It is a Curzon number.

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, 202110056 + ... + 202110065.

It is an arithmetic number, because the mean of its divisors is an integer number (606330183).

Almost surely, 2^2021100605 is an apocalyptic number.

It is an amenable number.

2021100605 is a deficient number, since it is larger than the sum of its proper divisors (404220127).

2021100605 is an equidigital number, since it uses as much as digits as its factorization.

2021100605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404220126.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 2021100605 is about 44956.6525110578. The cubic root of 2021100605 is about 1264.3364077231.

Adding to 2021100605 its reverse (5060011202), we get a palindrome (7081111807).

The spelling of 2021100605 in words is "two billion, twenty-one million, one hundred thousand, six hundred five".