21044115 has 48 divisors (see below), whose sum is σ = 38887680. Its totient is φ = 10497600.

The previous prime is 21044081. The next prime is 21044117. The reversal of 21044115 is 51144012.

21044115 is a `hidden beast` number, since 210 + 441 + 15 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-21044115 is a prime.

It is a super-2 number, since 2×21044115² = 885709552266450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21044117) 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 47 ways as a sum of consecutive naturals, for example, 129024 + ... + 129186.

It is an arithmetic number, because the mean of its divisors is an integer number (810160).

Almost surely, 2^21044115 is an apocalyptic number.

21044115 is a deficient number, since it is larger than the sum of its proper divisors (17843565).

21044115 is a wasteful number, since it uses less digits than its factorization.

21044115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 344 (or 341 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 21044115 is about 4587.3865108578. The cubic root of 21044115 is about 276.0854728975.

Adding to 21044115 its reverse (51144012), we get a palindrome (72188127).

The spelling of 21044115 in words is "twenty-one million, forty-four thousand, one hundred fifteen".