21022845 has 16 divisors (see below), whose sum is σ = 34546560. Its totient is φ = 10908864.

The previous prime is 21022817. The next prime is 21022849. The reversal of 21022845 is 54822012.

It is not a de Polignac number, because 21022845 - 2¹⁶ = 20957309 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18385 + ... + 19494.

It is an arithmetic number, because the mean of its divisors is an integer number (2159160).

Almost surely, 2^21022845 is an apocalyptic number.

It is an amenable number.

21022845 is a deficient number, since it is larger than the sum of its proper divisors (13523715).

21022845 is a wasteful number, since it uses less digits than its factorization.

21022845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37924.

The product of its (nonzero) digits is 1280, while the sum is 24.

The square root of 21022845 is about 4585.0676112790. The cubic root of 21022845 is about 275.9924252279.

Adding to 21022845 its reverse (54822012), we get a palindrome (75844857).

The spelling of 21022845 in words is "twenty-one million, twenty-two thousand, eight hundred forty-five".