2021775605 has 4 divisors (see below), whose sum is σ = 2426130732. Its totient is φ = 1617420480.

The previous prime is 2021775599. The next prime is 2021775607. The reversal of 2021775605 is 5065771202.

It is a happy number.

2021775605 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

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 299774596 + 1722001009 = 17314^2 + 41497^2 .

It is not a de Polignac number, because 2021775605 - 2⁴ = 2021775589 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021775607) 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, 202177556 + ... + 202177565.

It is an arithmetic number, because the mean of its divisors is an integer number (606532683).

Almost surely, 2^2021775605 is an apocalyptic number.

It is an amenable number.

2021775605 is a deficient number, since it is larger than the sum of its proper divisors (404355127).

2021775605 is an equidigital number, since it uses as much as digits as its factorization.

2021775605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404355126.

The product of its (nonzero) digits is 29400, while the sum is 35.

The square root of 2021775605 is about 44964.1591159003. The cubic root of 2021775605 is about 1264.4771449172.

The spelling of 2021775605 in words is "two billion, twenty-one million, seven hundred seventy-five thousand, six hundred five".