645003125 has 24 divisors (see below), whose sum is σ = 868272552. Its totient is φ = 476280000.

The previous prime is 645003091. The next prime is 645003131. The reversal of 645003125 is 521300546.

It can be written as a sum of positive squares in 12 ways, for example, as 612216049 + 32787076 = 24743^2 + 5726^2 .

It is not a de Polignac number, because 645003125 - 2⁶ = 645003061 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 645003094 and 645003103.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 32687 + ... + 48563.

It is an arithmetic number, because the mean of its divisors is an integer number (36178023).

Almost surely, 2^645003125 is an apocalyptic number.

645003125 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

645003125 is a deficient number, since it is larger than the sum of its proper divisors (223269427).

645003125 is an equidigital number, since it uses as much as digits as its factorization.

645003125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15915 (or 15895 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 26.

The square root of 645003125 is about 25396.9117217035. The cubic root of 645003125 is about 864.0136551376.

The spelling of 645003125 in words is "six hundred forty-five million, three thousand, one hundred twenty-five".