21103225 has 24 divisors (see below), whose sum is σ = 30748032. Its totient is φ = 14164800.

The previous prime is 21103217. The next prime is 21103241. The reversal of 21103225 is 52230112.

It is not a de Polignac number, because 21103225 - 2³ = 21103217 is a prime.

It is a super-2 number, since 2×21103225² = 890692210801250, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21103199 and 21103208.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 624 + ... + 6526.

It is an arithmetic number, because the mean of its divisors is an integer number (1281168).

Almost surely, 2^21103225 is an apocalyptic number.

21103225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21103225 is a deficient number, since it is larger than the sum of its proper divisors (9644807).

21103225 is a wasteful number, since it uses less digits than its factorization.

21103225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5937 (or 5932 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 21103225 is about 4593.8246592573. The cubic root of 21103225 is about 276.3437265145.

Adding to 21103225 its reverse (52230112), we get a palindrome (73333337).

It can be divided in two parts, 2110 and 3225, that added together give a palindrome (5335).

The spelling of 21103225 in words is "twenty-one million, one hundred three thousand, two hundred twenty-five".