1644425225 has 24 divisors (see below), whose sum is σ = 2161790208. Its totient is φ = 1238673600.

The previous prime is 1644425219. The next prime is 1644425231. The reversal of 1644425225 is 5225244461.

It is an interprime number because it is at equal distance from previous prime (1644425219) and next prime (1644425231).

It is not a de Polignac number, because 1644425225 - 2⁶ = 1644425161 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2 + ... + 57348.

It is an arithmetic number, because the mean of its divisors is an integer number (90074592).

Almost surely, 2^1644425225 is an apocalyptic number.

It is an amenable number.

1644425225 is a deficient number, since it is larger than the sum of its proper divisors (517364983).

1644425225 is a wasteful number, since it uses less digits than its factorization.

With its successor (1644425226) it forms a Ruth-Aaron pair, since the sum of their prime factors is the same (57425).

1644425225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57425 (or 57420 counting only the distinct ones).

The product of its digits is 76800, while the sum is 35.

The square root of 1644425225 is about 40551.5132270055. The cubic root of 1644425225 is about 1180.3334366049. Note that the first 3 decimals are identical.

Adding to 1644425225 its reverse (5225244461), we get a palindrome (6869669686).

The spelling of 1644425225 in words is "one billion, six hundred forty-four million, four hundred twenty-five thousand, two hundred twenty-five".