21103115 has 8 divisors (see below), whose sum is σ = 27625968. Its totient is φ = 15347680.

The previous prime is 21103109. The next prime is 21103123. The reversal of 21103115 is 51130112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21103115 - 2⁶ = 21103051 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21103115.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 191792 + ... + 191901.

It is an arithmetic number, because the mean of its divisors is an integer number (3453246).

Almost surely, 2^21103115 is an apocalyptic number.

21103115 is a deficient number, since it is larger than the sum of its proper divisors (6522853).

21103115 is a wasteful number, since it uses less digits than its factorization.

21103115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 383709.

The product of its (nonzero) digits is 30, while the sum is 14.

The square root of 21103115 is about 4593.8126866471. The cubic root of 21103115 is about 276.3432463689.

Adding to 21103115 its reverse (51130112), we get a palindrome (72233227).

It can be divided in two parts, 2110 and 3115, that added together give a palindrome (5225).

The spelling of 21103115 in words is "twenty-one million, one hundred three thousand, one hundred fifteen".