21030115 has 4 divisors (see below), whose sum is σ = 25236144. Its totient is φ = 16824088.

The previous prime is 21030109. The next prime is 21030127. The reversal of 21030115 is 51103012.

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

It is a cyclic number.

It is not a de Polignac number, because 21030115 - 2⁵ = 21030083 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21030095 and 21030104.

It is an unprimeable number.

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, 2103007 + ... + 2103016.

It is an arithmetic number, because the mean of its divisors is an integer number (6309036).

Almost surely, 2^21030115 is an apocalyptic number.

21030115 is a deficient number, since it is larger than the sum of its proper divisors (4206029).

21030115 is an equidigital number, since it uses as much as digits as its factorization.

21030115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4206028.

The product of its (nonzero) digits is 30, while the sum is 13.

The square root of 21030115 is about 4585.8603336779. The cubic root of 21030115 is about 276.0242356020.

Adding to 21030115 its reverse (51103012), we get a palindrome (72133127).

The spelling of 21030115 in words is "twenty-one million, thirty thousand, one hundred fifteen".