21230113 has 4 divisors (see below), whose sum is σ = 21246868. Its totient is φ = 21213360.

The previous prime is 21230047. The next prime is 21230123. The reversal of 21230113 is 31103212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3732624 + 17497489 = 1932^2 + 4183^2 .

It is a cyclic number.

It is not a de Polignac number, because 21230113 - 2¹⁷ = 21099041 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21230093 and 21230102.

It is not an unprimeable number, because it can be changed into a prime (21230123) 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 3 ways as a sum of consecutive naturals, for example, 6306 + ... + 9067.

It is an arithmetic number, because the mean of its divisors is an integer number (5311717).

Almost surely, 2^21230113 is an apocalyptic number.

It is an amenable number.

21230113 is a deficient number, since it is larger than the sum of its proper divisors (16755).

21230113 is a wasteful number, since it uses less digits than its factorization.

21230113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16754.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 21230113 is about 4607.6146757297. The cubic root of 21230113 is about 276.8964802349.

Adding to 21230113 its reverse (31103212), we get a palindrome (52333325).

The spelling of 21230113 in words is "twenty-one million, two hundred thirty thousand, one hundred thirteen".