21033845 has 64 divisors (see below), whose sum is σ = 33592320. Its totient is φ = 12300288.

The previous prime is 21033827. The next prime is 21033853. The reversal of 21033845 is 54833012.

It is not a de Polignac number, because 21033845 - 2⁶ = 21033781 is a prime.

It is a congruent number.

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 396839 + ... + 396891.

It is an arithmetic number, because the mean of its divisors is an integer number (524880).

Almost surely, 2^21033845 is an apocalyptic number.

It is an amenable number.

21033845 is a deficient number, since it is larger than the sum of its proper divisors (12558475).

21033845 is a wasteful number, since it uses less digits than its factorization.

21033845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 21033845 is about 4586.2670005136. The cubic root of 21033845 is about 276.0405536223.

Adding to 21033845 its reverse (54833012), we get a palindrome (75866857).

The spelling of 21033845 in words is "twenty-one million, thirty-three thousand, eight hundred forty-five".