2021617 has 4 divisors (see below), whose sum is σ = 2177140. Its totient is φ = 1866096.

The previous prime is 2021609. The next prime is 2021627. The reversal of 2021617 is 7161202.

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 776161 + 1245456 = 881^2 + 1116^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021617 - 2³ = 2021609 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2021594 and 2021603.

It is not an unprimeable number, because it can be changed into a prime (2021627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 77742 + ... + 77767.

It is an arithmetic number, because the mean of its divisors is an integer number (544285).

2^2021617 is an apocalyptic number.

It is an amenable number.

2021617 is a deficient number, since it is larger than the sum of its proper divisors (155523).

2021617 is a wasteful number, since it uses less digits than its factorization.

2021617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155522.

The product of its (nonzero) digits is 168, while the sum is 19.

The square root of 2021617 is about 1421.8357851735. The cubic root of 2021617 is about 126.4444078662. Note that the first 4 decimals are identical.

Adding to 2021617 its reverse (7161202), we get a palindrome (9182819).

The spelling of 2021617 in words is "two million, twenty-one thousand, six hundred seventeen".