21103349 has 4 divisors (see below), whose sum is σ = 21370560. Its totient is φ = 20836140.

The previous prime is 21103339. The next prime is 21103363. The reversal of 21103349 is 94330112.

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 a cyclic number.

It is not a de Polignac number, because 21103349 - 2¹⁶ = 21037813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21103309) 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, 133487 + ... + 133644.

It is an arithmetic number, because the mean of its divisors is an integer number (5342640).

Almost surely, 2^21103349 is an apocalyptic number.

It is an amenable number.

21103349 is a deficient number, since it is larger than the sum of its proper divisors (267211).

21103349 is an equidigital number, since it uses as much as digits as its factorization.

21103349 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 267210.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 21103349 is about 4593.8381556167. The cubic root of 21103349 is about 276.3442677676.

The spelling of 21103349 in words is "twenty-one million, one hundred three thousand, three hundred forty-nine".