21103353 has 12 divisors (see below), whose sum is σ = 30638400. Its totient is φ = 13997016.

The previous prime is 21103339. The next prime is 21103363. The reversal of 21103353 is 35330112.

It is not a de Polignac number, because 21103353 - 2⁴ = 21103337 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21103363) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4101 + ... + 7682.

It is an arithmetic number, because the mean of its divisors is an integer number (2553200).

Almost surely, 2^21103353 is an apocalyptic number.

It is an amenable number.

21103353 is a deficient number, since it is larger than the sum of its proper divisors (9535047).

21103353 is a wasteful number, since it uses less digits than its factorization.

21103353 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11988 (or 11985 counting only the distinct ones).

The product of its (nonzero) digits is 270, while the sum is 18.

The square root of 21103353 is about 4593.8385909825. The cubic root of 21103353 is about 276.3442852273.

Adding to 21103353 its reverse (35330112), we get a palindrome (56433465).

It can be divided in two parts, 2 and 1103353, that added together give a triangular number (1103355 = T₁₄₈₅).

The spelling of 21103353 in words is "twenty-one million, one hundred three thousand, three hundred fifty-three".