21222451225 has 6 divisors (see below), whose sum is σ = 26315839550. Its totient is φ = 16977960960.

The previous prime is 21222451193. The next prime is 21222451241. The reversal of 21222451225 is 52215422212.

It can be written as a sum of positive squares in 3 ways, for example, as 2252071936 + 18970379289 = 47456^2 + 137733^2 .

It is not a de Polignac number, because 21222451225 - 2⁵ = 21222451193 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21222451193 and 21222451202.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 424449000 + ... + 424449049.

Almost surely, 2^21222451225 is an apocalyptic number.

21222451225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21222451225 is a deficient number, since it is larger than the sum of its proper divisors (5093388325).

21222451225 is an equidigital number, since it uses as much as digits as its factorization.

21222451225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 848898059 (or 848898054 counting only the distinct ones).

The product of its digits is 6400, while the sum is 28.

Adding to 21222451225 its reverse (52215422212), we get a palindrome (73437873437).

The spelling of 21222451225 in words is "twenty-one billion, two hundred twenty-two million, four hundred fifty-one thousand, two hundred twenty-five".