21043113 has 16 divisors (see below), whose sum is σ = 34532736. Its totient is φ = 11099520.

The previous prime is 21043111. The next prime is 21043123. The reversal of 21043113 is 31134012.

It is not a de Polignac number, because 21043113 - 2¹ = 21043111 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21043092 and 21043101.

It is not an unprimeable number, because it can be changed into a prime (21043111) 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, 38268 + ... + 38813.

It is an arithmetic number, because the mean of its divisors is an integer number (2158296).

Almost surely, 2^21043113 is an apocalyptic number.

It is an amenable number.

21043113 is a deficient number, since it is larger than the sum of its proper divisors (13489623).

21043113 is a wasteful number, since it uses less digits than its factorization.

21043113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77104.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 21043113 is about 4587.2772970467. The cubic root of 21043113 is about 276.0810909593.

Adding to 21043113 its reverse (31134012), we get a palindrome (52177125).

The spelling of 21043113 in words is "twenty-one million, forty-three thousand, one hundred thirteen".