645167725 has 12 divisors (see below), whose sum is σ = 800478900. Its totient is φ = 515830400.

The previous prime is 645167701. The next prime is 645167729. The reversal of 645167725 is 527761546.

It can be written as a sum of positive squares in 6 ways, for example, as 88868329 + 556299396 = 9427^2 + 23586^2 .

It is not a de Polignac number, because 645167725 - 2⁹ = 645167213 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645167729) by changing a digit.

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, 42105 + ... + 55345.

It is an arithmetic number, because the mean of its divisors is an integer number (66706575).

Almost surely, 2^645167725 is an apocalyptic number.

It is an amenable number.

645167725 is a deficient number, since it is larger than the sum of its proper divisors (155311175).

645167725 is a wasteful number, since it uses less digits than its factorization.

645167725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15200 (or 15195 counting only the distinct ones).

The product of its digits is 352800, while the sum is 43.

The square root of 645167725 is about 25400.1520664739. The cubic root of 645167725 is about 864.0871455059.

The spelling of 645167725 in words is "six hundred forty-five million, one hundred sixty-seven thousand, seven hundred twenty-five".