21103297 has 4 divisors (see below), whose sum is σ = 21461040. Its totient is φ = 20745556.

The previous prime is 21103267. The next prime is 21103301. The reversal of 21103297 is 79230112.

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 a de Polignac number, because none of the positive numbers 2^k-21103297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21103207) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 178783 + ... + 178900.

It is an arithmetic number, because the mean of its divisors is an integer number (5365260).

Almost surely, 2^21103297 is an apocalyptic number.

It is an amenable number.

21103297 is a deficient number, since it is larger than the sum of its proper divisors (357743).

21103297 is an equidigital number, since it uses as much as digits as its factorization.

21103297 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 357742.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 21103297 is about 4593.8324958579. The cubic root of 21103297 is about 276.3440407908.

The spelling of 21103297 in words is "twenty-one million, one hundred three thousand, two hundred ninety-seven".