645507136 has 28 divisors (see below), whose sum is σ = 1356279228. Its totient is φ = 303767552.

The previous prime is 645507133. The next prime is 645507211. The reversal of 645507136 is 631705546.

It can be written as a sum of positive squares in 2 ways, for example, as 588353536 + 57153600 = 24256^2 + 7560^2 .

It is a junction number, because it is equal to n+sod(n) for n = 645507095 and 645507104.

It is not an unprimeable number, because it can be changed into a prime (645507131) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 295561 + ... + 297736.

Almost surely, 2^645507136 is an apocalyptic number.

It is an amenable number.

645507136 is an abundant number, since it is smaller than the sum of its proper divisors (710772092).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

645507136 is a wasteful number, since it uses less digits than its factorization.

645507136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 593326 (or 593316 counting only the distinct ones).

The product of its (nonzero) digits is 75600, while the sum is 37.

The square root of 645507136 is about 25406.8324668779. The cubic root of 645507136 is about 864.2386457830.

The spelling of 645507136 in words is "six hundred forty-five million, five hundred seven thousand, one hundred thirty-six".