21103315 has 16 divisors (see below), whose sum is σ = 26199936. Its totient is φ = 16307200.

The previous prime is 21103309. The next prime is 21103321. The reversal of 21103315 is 51330112.

It is an interprime number because it is at equal distance from previous prime (21103309) and next prime (21103321).

It is a de Polignac number, because none of the positive numbers 2^k-21103315 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22710 + ... + 23620.

It is an arithmetic number, because the mean of its divisors is an integer number (1637496).

Almost surely, 2^21103315 is an apocalyptic number.

21103315 is a deficient number, since it is larger than the sum of its proper divisors (5096621).

21103315 is a wasteful number, since it uses less digits than its factorization.

21103315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1070.

The product of its (nonzero) digits is 90, while the sum is 16.

The square root of 21103315 is about 4593.8344550060. The cubic root of 21103315 is about 276.3441193597.

Adding to 21103315 its reverse (51330112), we get a palindrome (72433427).

The spelling of 21103315 in words is "twenty-one million, one hundred three thousand, three hundred fifteen".