21425210501225 has 24 divisors (see below), whose sum is σ = 26740742654808. Its totient is φ = 17028279590400.

The previous prime is 21425210501129. The next prime is 21425210501239. The reversal of 21425210501225 is 52210501252412.

It can be written as a sum of positive squares in 12 ways, for example, as 3352619592256 + 18072590908969 = 1831016^2 + 4251187^2 .

It is a de Polignac number, because none of the positive numbers 2^k-21425210501225 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21425210501191 and 21425210501200.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 24362165 + ... + 25226285.

It is an arithmetic number, because the mean of its divisors is an integer number (1114197610617).

Almost surely, 2^{21425210501225} is an apocalyptic number.

21425210501225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21425210501225 is a deficient number, since it is larger than the sum of its proper divisors (5315532153583).

21425210501225 is a wasteful number, since it uses less digits than its factorization.

21425210501225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 870605 (or 870600 counting only the distinct ones).

The product of its (nonzero) digits is 16000, while the sum is 32.

Adding to 21425210501225 its reverse (52210501252412), we get a palindrome (73635711753637).

The spelling of 21425210501225 in words is "twenty-one trillion, four hundred twenty-five billion, two hundred ten million, five hundred one thousand, two hundred twenty-five".