2021564 has 12 divisors (see below), whose sum is σ = 3613344. Its totient is φ = 989184.

The previous prime is 2021563. The next prime is 2021567. The reversal of 2021564 is 4651202.

It is a happy number.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021563) 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, 5189 + ... + 5564.

It is an arithmetic number, because the mean of its divisors is an integer number (301112).

2^2021564 is an apocalyptic number.

It is an amenable number.

2021564 is a deficient number, since it is larger than the sum of its proper divisors (1591780).

2021564 is a wasteful number, since it uses less digits than its factorization.

2021564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10804 (or 10802 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 2021564 is about 1421.8171471747. The cubic root of 2021564 is about 126.4433028742.

Adding to 2021564 its reverse (4651202), we get a palindrome (6672766).

The spelling of 2021564 in words is "two million, twenty-one thousand, five hundred sixty-four".