645512013 has 6 divisors (see below), whose sum is σ = 932406254. Its totient is φ = 430341336.

The previous prime is 645511967. The next prime is 645512017. The reversal of 645512013 is 310215546.

645512013 is a `hidden beast` number, since 6 + 455 + 1 + 201 + 3 = 666.

It can be written as a sum of positive squares in only one way, i.e., 377796969 + 267715044 = 19437^2 + 16362^2 .

It is not a de Polignac number, because 645512013 - 2⁶ = 645511949 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645512017) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35861770 + ... + 35861787.

Almost surely, 2^645512013 is an apocalyptic number.

It is an amenable number.

645512013 is a deficient number, since it is larger than the sum of its proper divisors (286894241).

645512013 is a wasteful number, since it uses less digits than its factorization.

645512013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71723563 (or 71723560 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 645512013 is about 25406.9284448160. The cubic root of 645512013 is about 864.2408223049.

Adding to 645512013 its reverse (310215546), we get a palindrome (955727559).

It can be divided in two parts, 64551 and 2013, that added together give a square (66564 = 258²).

The spelling of 645512013 in words is "six hundred forty-five million, five hundred twelve thousand, thirteen".