2021655 has 8 divisors (see below), whose sum is σ = 3234672. Its totient is φ = 1078208.

The previous prime is 2021653. The next prime is 2021659. The reversal of 2021655 is 5561202.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2021655 - 2¹ = 2021653 is a prime.

2021655 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021651) 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 7 ways as a sum of consecutive naturals, for example, 67374 + ... + 67403.

It is an arithmetic number, because the mean of its divisors is an integer number (404334).

2^2021655 is an apocalyptic number.

2021655 is a deficient number, since it is larger than the sum of its proper divisors (1213017).

2021655 is a wasteful number, since it uses less digits than its factorization.

2021655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134785.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 2021655 is about 1421.8491481166. The cubic root of 2021655 is about 126.4452001128.

Subtracting from 2021655 its product of nonzero digits (600), we obtain a triangular number (2021055 = T₂₀₁₀).

Adding to 2021655 its reverse (5561202), we get a palindrome (7582857).

The spelling of 2021655 in words is "two million, twenty-one thousand, six hundred fifty-five".