21242422225 has 12 divisors (see below), whose sum is σ = 27485847936. Its totient is φ = 16255070480.

The previous prime is 21242422177. The next prime is 21242422247. The reversal of 21242422225 is 52222424212.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-21242422225 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21242422193 and 21242422202.

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 11 ways as a sum of consecutive naturals, for example, 18471097 + ... + 18472246.

It is an arithmetic number, because the mean of its divisors is an integer number (2290487328).

Almost surely, 2^21242422225 is an apocalyptic number.

21242422225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21242422225 is a deficient number, since it is larger than the sum of its proper divisors (6243425711).

21242422225 is a wasteful number, since it uses less digits than its factorization.

21242422225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36943376 (or 36943371 counting only the distinct ones).

The product of its digits is 10240, while the sum is 28.

Adding to 21242422225 its reverse (52222424212), we get a palindrome (73464846437).

The spelling of 21242422225 in words is "twenty-one billion, two hundred forty-two million, four hundred twenty-two thousand, two hundred twenty-five".