645204313 has 6 divisors (see below), whose sum is σ = 698653374. Its totient is φ = 595573056.

The previous prime is 645204311. The next prime is 645204341. The reversal of 645204313 is 313402546.

It can be written as a sum of positive squares in 3 ways, for example, as 12581209 + 632623104 = 3547^2 + 25152^2 .

It is not a de Polignac number, because 645204313 - 2¹ = 645204311 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645204311) 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, 1908720 + ... + 1909057.

It is an arithmetic number, because the mean of its divisors is an integer number (116442229).

Almost surely, 2^645204313 is an apocalyptic number.

It is an amenable number.

645204313 is a deficient number, since it is larger than the sum of its proper divisors (53449061).

645204313 is a wasteful number, since it uses less digits than its factorization.

645204313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3817803 (or 3817790 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 28.

The square root of 645204313 is about 25400.8722881715. The cubic root of 645204313 is about 864.1034795648.

Adding to 645204313 its reverse (313402546), we get a palindrome (958606859).

The spelling of 645204313 in words is "six hundred forty-five million, two hundred four thousand, three hundred thirteen".