21103113 has 4 divisors (see below), whose sum is σ = 28137488. Its totient is φ = 14068740.

The previous prime is 21103109. The next prime is 21103123. The reversal of 21103113 is 31130112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21103113 - 2² = 21103109 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21103123) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3517183 + ... + 3517188.

It is an arithmetic number, because the mean of its divisors is an integer number (7034372).

Almost surely, 2^21103113 is an apocalyptic number.

It is an amenable number.

21103113 is a deficient number, since it is larger than the sum of its proper divisors (7034375).

21103113 is an equidigital number, since it uses as much as digits as its factorization.

21103113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7034374.

The product of its (nonzero) digits is 18, while the sum is 12.

The square root of 21103113 is about 4593.8124689630. The cubic root of 21103113 is about 276.3432376390.

Adding to 21103113 its reverse (31130112), we get a palindrome (52233225).

The spelling of 21103113 in words is "twenty-one million, one hundred three thousand, one hundred thirteen".