645136225 has 12 divisors (see below), whose sum is σ = 803409516. Its totient is φ = 513889280.

The previous prime is 645136211. The next prime is 645136237. The reversal of 645136225 is 522631546.

It can be written as a sum of positive squares in 6 ways, for example, as 331776 + 644804449 = 576^2 + 25393^2 .

It is not a de Polignac number, because 645136225 - 2⁹ = 645135713 is a prime.

It is a Duffinian 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 11 ways as a sum of consecutive naturals, for example, 49552 + ... + 61201.

It is an arithmetic number, because the mean of its divisors is an integer number (66950793).

Almost surely, 2^645136225 is an apocalyptic number.

It is an amenable number.

645136225 is a deficient number, since it is larger than the sum of its proper divisors (158273291).

645136225 is a wasteful number, since it uses less digits than its factorization.

645136225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110996 (or 110991 counting only the distinct ones).

The product of its digits is 43200, while the sum is 34.

The square root of 645136225 is about 25399.5319838772. The cubic root of 645136225 is about 864.0730823990.

The spelling of 645136225 in words is "six hundred forty-five million, one hundred thirty-six thousand, two hundred twenty-five".